Tektronix 7072 Instruction Manual
Instruction Manual
Model 7072
Semiconductor Matrix Card
Contains Operating and Servicing Information
WARRANTY
Keithley Instruments, Inc. warrants this product to he free from defects in material and workmanship for a period of I year from
date of shipment.
Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: prohcs, cahlcs, rcchargcahlc hattcrits, diskcttcs, and documentation
During tbc warranty period, we will, at our option, either repair or replace any product that proves to he defective.
To exercise this warranty, write or call your local Keithley representative, or contact Keithley headquarters in Clcvcland, Ohio. You
will he given prompt assistance and return instructions. Send the product, transportation prepaid, to the indicated service facility.
Repairs will he made and the product returned, transportation prepaid. Repaired or replaced products arc warranted for the halancc
of the original warranty period, or at last 90 days.
LIMITATION OF WARRANTY
This warranty does not apply to defects resulting from product modification without Keithley’s express written consent, or misuse
of any product or part. This warranty also does not apply to fuses, software, non-rechargeahlc battcrics, damage from battery leakage, or prohlcms arising from normal wear or failure to follow instructions.
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING ANY IMPLIED
WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. THE REMEDIES PROVIDED HEREIN
ARE BUYER’S SOLE AND EXCLUSIVE REMEDIES.
NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT,
INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF: ITS INSTRU-
MENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS, INC., HAS BEEN ADVISED IN ADVANCE OF THE POSSIBILITY OF SUCH DAMAGES. SUCH EXCLUDED DAMAGES SHALL INCLUDE, BUT ARE NOT LIMITED TO: COSTS
OF REMOVAL AND INSTALLATION, LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERSON, OR DAM-
AGE TO PROPERTY.
STATEMENT OF CALIBRATION
This instrument has hecn inspcctcd and tested in accordance with specifications puhlishcd by Kcithlcy Instruments, Inc.
The accuracy and calibration of this instrument al-c traceahlc to the National Bureau of Standards through cquipmcnt which is cali-
brated at planned intervals by comparison to certified standards maintained in the Laboratories of Kcithlcy Instruments, Inc.
Model 7072 Semiconductor Matrix Card
Instruction Manual
01988, Keithley Instruments, Inc.
All rights reserved.
Cleveland, Ohio, U.S.A.
Third Printing, April 2000
Document Number: 7072-901-01 Rev. C
Manual Print History
The print history shown below lists the printing dates of all Revisions and Addenda created for this manual. The
Revision Level letter increases ,II ‘ phabetically as the manual undergoes subsequent updates. Addenda, which arc
released between Revisions, contain important change information that the user should incorporate immcdiatcly into
the manual. Addenda arc numbcrcd sequentially. When a new Revision is created, all Addenda associated with the
previous Revision of the manual are incorporated into the new Revision of the manual. Each new Revision includes
a revised copy of this print history page.
Revision A (Document Numbcr 7072-901-01) ... .................... ................... February lY88
Revision B (Document Number 7072-901-01) ......................................... ......... April I988
Addendum B (Document Number 7072-901-02). ............................................... April I988
Addendum B (Document Numbcr 7072-901-03). ......................................... February I996
Revision C (Document Number 7072-901-01) ,...............................,.......,.....,.., April 2000
Safety Precautions
The following safety precautions should be observed before using
this product and any associated instrumentation. Although some in~tmmcnt~ and accessories would normally be used with non-hazardous voltages, there are sitilafions when hazardous conditions
may be prcscnt.
This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions rcquired to avoid possible injury Read the operating information
carefully before using the product.
The types of product users are:
Responsible body is the individual or group responsible for the use
and maintenance of equipment, for ensuring that the equipment is
operated within its specifications and operating limits, and for ensuring that operators are adequately trained.
Operators use the product for its intended function. They must be
trained in electrical safety procedures and proper use of the instrument. They must be protected from electric shock and contact with
hazardous live circuits.
Maintenance personnel perform routine procedures on the product
to keep it operating, for example, setting the line voltage or replacing consumable materials. Maintenance procedures are described in
the manual. The procedures explicitly state ifthe operator may perform them, Otherwise, they should be performed only by service
personnel.
Service personnel are trained to work on live circuits, and perform
safe installations and repairs ofproducts. Only properly trained service personnel may perform installation and service procedures.
Users of this product must bc protected from electric shock at all
times. The responsible body must ensure that users are prevented
access and/or insulated from every connection point. In some cases,
connections must be exposed to potential human contact. Product
users in these circumstances must bc trained to protect themsclvcs
from the risk of electric shock. If the circuit is capable of operating
at or above 1000 volts, no conductive part of the circuit may be
exposed.
As described in the International Electrotechnical Commission
(IEC) Standard IEC 664, digital multimctcr measuring circuits
(e.g., Keithley Models 175.A. 199,2000,2001,2002, and 2010) are
Installation Category II. All other instruments’signal terminals are
Installation Category I and must not be connected to mains.
Do not connect switching cards directly to unlimited power circuits.
They are intended to be used with impedance limited sources.
NEVER connect switching cards directly to AC mains. When con-
necting sources to switching cards, install protective devices to limit fault current and voltage to the card.
Bcforc operating an instrument, make sure the line cord is connected to a properly grounded power receptacle. Inspect the connecting
cables, test leads, and jumpers for possible wear, cracks, or breaks
before each use.
For maximum safety, do not touch the product, test cables, or any
other instruments while power is applied to the circuit under test.
ALWAYS remove power from the cntire test system and discharge
any capacitors before: connecting or disconnecting cables or jumpers, installing or removing switching cards, or making internal
changes, such as installing or removing jumpers.
Exercise extreme caution when a shock hazard is present. Lethal
voltage may be present on cable connector jacks or test fixtures. The
American National Standards Institute (ANSI) states that a shock
hazard exists when voltage levels greater than 30V RMS, 42.4V
peak, or 60VDC are present. A good safety practice is to expect
that hazardous voltage is present in any unknown circuit before
measuring.
Do not touch any object that could provide a current path to the
common side of the circuit under test or power line (earth) ground.
Always make measurements with dly hands while standing on a
dry, insulated surface capable of withstanding the voltage being
measured.
The instrument and accessories must be used in accordance with its
specifications and operating instructions or the safety oftbe equipment may be impaired.
The WARNING heading in a manual explains dangers that might
result in personal injury or death. Always read the associated information very carefully before performing the indicated procedure.
Do not exceed the maximum signal levels ofthe instruments and accessories, as defined in the specifications and operating information, and us shown on the instrument or test fixture panels, or
switching card.
When fuses are used in a product, replace with same type and rating
for continued protection against fire hazard.
Chassis connections must only be used as shield connections for
measuring circuits, NOT as safety earth ground connections.
If you are using a test fixture, keep the lid closed while power is up-
plied to the device under test. Safe operation requires the use of a
lid interlock.
Ifa @
screw is present, connect it to safety earth ground using the
wire recommended in the user documentation.
Then symbol on a” instrument indicates that the user should re-
fer to the operating instructions located in the manual.
Them
symbol on an instrument shows that it can source or mcasure 1000 volts or mom, including the combined effect of normal
and c”,,,,,,~” mode voltages. Use standard safety precautions to
avoid personal contact with these voltages.
The CAUTION heading in a manual explains hazards that could
damage the instmmcnt. Such damage may invalidate the warranty.
Instrumentation and accessories shall not be connected to humans.
Before performing any maintenance, disconnect the line cord and
all test cables.
To maintain protection from electric shock and fire, replaccmcnt
components in mains circuits, including the power transformer, test
leads, and input jacks, must be purchased from Kcithlcy Instm-
men& Standard fuses, with applicable national safety approvals,
may be used if the rating and type are the same. Other components
that are not safety related may be purchased from other suppliers as
long as they are equivalent to the original component. (Note that selected pans should be purchased only through Keithlcy Instruments
to maintain accuracy and functionality of the product.) If you are
unsure about the applicability of a replacement component, call a
Keithley Instruments office for information.
To clean an instrument, use a damp cloth or mild, water based
cleaner. Clean the exterior of the instrument only. Do not apply
cleaner directly to the instrument or allow liquids to enter or spill
on the instrument. Products that consist of a circuit board with no
case or chassis (C&L data acquisition board for installation into a
computer) should “ever require cleaning if handled according to instructions. If the board bccames contaminated and operation is affected, the board should be returned to the factory for proper
clca”i”glservici”g.
Rev. IO199
SAFETY PRECAUTIONS
The following safety precautions should be observed before using the Model 7072 and the associated
instruments.
This matrix card is intended for use by qualified personnel who recognize shock hazards and are familiar
with the safety precautions required to avoid possible injury. Read over this manual carefully before
using the matrix card.
Exercise extreme caution when a shock hazard is present at the test circuit. User-supplied lethal voltages
may be present on the card connector jacks. The American National Standards Institute (ANSI) states
that a shock hazard exists when voltage levels greater than 30V RMS or 42.4V peak are present. A good
safety practice is to expect that hazardous voltage is present in any unknown circuit before measuring.
Do not exceed 200V between any two pins or between any pin and earth ground
Inspect the connecting cables and test leads for possible wear, cracks, or breaks before each use.
For maximum safety, do not touch the test cables or any instruments while power is applied to the
circuit under test. Turn off the power and discharge any capacitors before connecting or disconnecting
cables from the matrix card.
Do not touch any object which could provide a current path to the common side of the circuit under
test or power line (earth) ground. Always make measurements with dry hands while standing on a
dry, insulated surface capable of withstanding the voltage being measured.
Do not exceed the maximum allowable input of the matrix card, as defined in the specifications and
operation section of this manual.
7072 8×12 Semiconductor Matrix Card
MATRIX CONFIGURATION: 8 rows by 12
columns.
CONNECTOR TYPE: 3-lug triaxial (Signal,
Guard, Chassis).
MAXIMUM SIGNAL LEVEL: 200V, 1A
carry/0.5A switched, 10VA peak (resistive
load).
COMMON MODE VOLTAGE: 200V maxi-
mum between any 2 pins or chassis.
CONTACT LIFE: Cold Switching: 10
sures. At Maximum Signal Level: 10
sures.
PATH RESISTANCE (per conductor):<1Ω
initial, <3.5Ω at end of contact life.
CONTACT POTENTIAL: <40µV per cross-
point (Signal to Guard).
7
clo-
5
clo-
RELAY SETTLING TIME: <15ms.
INSERTION LOSS (1MHz, 50Ωsource, 50Ω
load): 0.1dB typical.
EMC: Conforms to European Union Directive
89/336/EEC.
SAFETY: Conforms to European Union Directive
73/23/EEC (meets EN61010-1/IEC 1010).
ENVIRONMENT:
OFFSET CURRENT and PATH ISOLA-
TION Specifications: 23°C, <60% R.H.
Operating: 0° to 50°C, up to 35°C at 70%
R.H.
Storage: –25° to +65°C.
ACCESSORIES SUPPLIED: Instruction
manual and four SMB expansion cables
(C54-1).
ACCESSORIES AVAILABLE:
7078-TRX-BNC: 3-Lug Triax to BNC
7078-TRX-T: 3-Lug Triax Tee Adapter
7078-TRX-3: 3-Lug Triax Cable,
7078-TRX-10: 3-Lug Triax Cable,
7078-TBC: 3-Lug Female Triax Bulk
7078-CSHP: Cable Set to connect
Adapter
0.9m (3 ft)
3m (10 ft)
head Connector with
Cap
7072 to HP 4145
LOW-CURRENT GENERAL-PURPOSE C-V
(ROWS A - B) (ROWS C - F) (ROWS G - H)
CROSSPOINT 2-pole Form A 2-pole Form A 1-pole Form A,
CONFIGURATION: Common Guard
OFFSET CURRENT: a<1 pA <20 pA <20 pA
PATH ISOLATION:
Resistance: >10
Capacitance (nominal): 0.4 pF 1 pF 0.6 pF
CROSSTALK
1 MHz, 50Ωload (typical): <–50 dB <–40 dB <–50 dB
3dB BANDWIDTH (typical),
50Ω Load: 15 MHz 8 MHz 5 MHz
RELAY DRIVE CURRENT
(per crosspoint): 40 mA 60 mA 80 mA
HGCHGCHGCHGCHGCHGCHGCHGCHGCHGCHGCHGC
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
1
1
1
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
1
1
1
1
1
1
1
1
13
Ω >1012Ω >1012Ω
User
connections
and backplane
expansion
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
1
1
1
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
1
1
1
1
1
1
1
1
H
G
C
H
G
C
H
G
C
H
G
C
H
G
C
H
G
C
H
G
C
H
G
C
Low I
Paths
General
Purpose
Paths
C-V
Paths
Contains information on Model 7U72 features, specifications, and accessories.
SECTION 1
General Information
Details installation of the Model 7072 Semiconductor
Matrix Card within the Model 707 Switching Matrix,
covers card connections, and also discusses measurement considerations.
Gives four typical applications for the Model 7072, including combined quasistatic and high-frequency CV
measurements, semiconductor switching matrix, van
der Pauw resistivity measurements, and semiconductor parameter analysis.
-
Contains performance verification procedures, troubleshooting information and principles of operation for
the matrix card.
Lists replacement parts, and also includes component
layout and schematic drawings for the Model 7072.
Service Information
SECTION 2
Operation
SECTION 3
Applications
SECTION
4
SECTION 5
Replaceable Parts
I
Table of Contents
1
General Information
INTRODUCTION.. .............................................................................................................................................
FEATURES ........................................................................................................................................................
WARRANTY INFORMATION
MANUAL ADDENDA
SAFETY SYMBOLS AND TERMS..
SPECIFICATIONS .............................................................................................................................................
UNPACKING AND INSPECTION
Inspection for Damage..
Shipment Contents.. ....................................................................................................................................
Instruction Manual
REPACKING FOR SHIPMENT..
OPTIONAL ACCESSORIES
COAXIAL JUMPER ACCESS ..........................................................................................................................
2 Operation
INTRODUCTION ...............................................................................................................................................
HANDLING PRECAUTIONS
ENVIRONMENTAL CONSIDERATIONS
CARD INSTALLATION AND REMOVAL..
CONNECTIONS
Card Connectors.. ........................................................................................................................................
Recommended Cables and Adapters
Triaxial to Banana Plug Adapter Preparation
General Instrument Connections
Keithley Instrument Connections
Typical Test Fixture Connections..
MATRIX CONFIGURATION
Switching Matrix
Row and Column Isolators ........................................................................................................................
Pathway Considerations..
Internal Matrix Expansion .........................................................................................................................
External Matrix Expansion
l-1
l-1
......................................................................................................................... l-1
...................................................................................................................................... l-l
................................................................................................................
................................................................................................................... l-2
.............................................................................................................................. l-2
......................................................................................................................................
...................................................................................................................... l-2
............................................................................................................................. 1-2
...........................................................................................................................
......................................................................................................
...................................................................................................
................................................................................................................................................ 2-3
...........................................................................................................
.............................................................................................
.................................................................................................................
.............................................................................................................. 2-11
...........................................................................................................
......................................................................................................................... 2- 18
....................................................................................................................................... 2- 18
.......................................................................................................................... 2-20
.......................................................................................................................
I- I
I-I
1-2
1-2
l-2
2-l
2-I
2-I
2-l
2-3
2-4
2-4
2-5
2- 17
2-20
2-20
2-23
MEASUREMENT CONSIDERATIONS .........................................................................................................
Magnetic Fields .........................................................................................................................................
Electromagnetic Intcrfcrencc (EMI). .........................................................................................................
Ground Loops.. ..........................................................................................................................................
Keeping Connectors Clean ........................................................................................................................
Noise Currents Caused by Cable Flexing..
Shielding.. ..................................................................................................................................................
Guarding.. ..................................................................................................................................................
Matrix Expansion Effects on Card Spccilications..
3 Applications
2.24
2-24
2-25
2-25
2-26
................................................................................................ 2-26
2.26
2-28
................................................................................... 2-29
4
....
3. I
3-l
3-l
3-l
3-4
3-4
3-4
3-6
3-6
3-9
3-9
3-9
3-12
3- I3
3- I.5
3.15
INTRODUCTION.. .............................................................................................................................................
CV MEASUREMENTS.. ....................................................................................................................................
Stand AIonc System Configuration.. ...........................................................................................................
Computerized System Configuration ..........................................................................................................
Optimizing CV Measurement Accuracy
Basic CV Test Procedure.. ...........................................................................................................................
Typical CV Curves ......................................................................................................................................
SEMICONDUCTOR TEST MATRIX ...............................................................................................................
System Configuration.. ................................................................................................................................
Testing Common-Source Characteristic
RESlSTIVITY MEASUREMENTS ...................................................................................................................
Test Configuration ............................................................................................
Test Procedure.. ...........................................................................................................................................
Resistivity Calculations.. ........................
SEMICONDUCTOR PARAMETER ANALYSIS ,.,..,..................................................................,...,
System Configuration.. ..............................................................................................................................
Cable Connections.. ...................................................................................................................................
SPA Mcasuremcnt Considerations.. ..........................................................................................................
Typical Test Proccdurc.. ............................................................................................................................
.......................................................... ...........................
of FETs.. ...................................................................................... 3-8
.......................................... 3-9
................. .......................................................... ...
.........
..................
.............. 3.12
Service Information
INTRODUCTION
HANDLING AND CLEANING PRECAUTIONS
PERFORMANCE VERIFICATION.. .................................................................................................................
Environmental Conditions.. .........................................................................................................................
Recommended Test Equipment..
Relay Testing.. .............................................................................................................................................
Offset Current Verification.. ........................................................................................................................
Path Isolation Verification.. .........................................................................................................................
Path Resistance Verification.. ......................................................................................................................
SPECIAL HANDLING OF STATIC-SENSITIVE
TROUBLESHOOTING
Recommended Equipment
Using the Extcndcr Card
Troubleshooting Prwxdure
PRINCIPLES OF OPERATION..
Block Diagram..
ID Data Circuits.. .......................................................................................................................................
Relay Control..
Powcr-on Safeguard
Isolator Relays ...........................................................................................................................................
REAR SHIELD..
............................................................................................................................................... 4-I
............................................................................................ 4-I
4 -1
4-l
................................................................................................................. 4-l
4-2
4-3
4-S
4-7
DEVICES
.................................................................................................................................... 4-10
......................................................................................................................... 4-10
........................................................................................................................... 4-10
.......................................................................................................................
..................................................................................................................... 4 I2
......................................................................................................................................... 4-12
...........................................................................................................................................
.................................................................................................................................. 4-l 3
................................................................................................................................................
........................................................................
4 -IO
4-10
4 I3
4 I3
4 I3
4-13
ii
5 Replaceable Parts
INTRODUCTION.. .............................................................................................................................................
PARTS LISTS .....................................................................................................................................................
ORDERING INFORMATION ...........................................................................................................................
FACTORY SERVICE
COMPONENT LAYOUT AND
........................................................................................................................................
SCHEMATIC DIAGRAM.. ........................................................................... 5-1
5-I
5-I
5-I
5-I
111
List of Illustrations
2
Figure 2. I
Figure 2-2
Figure 2-3
Figure 2-4
Figure 2-5
Figure 2-6
Figure 2-7
Figure 2-8
Figure 2-9
Figure 2-10
Figure 2-l 1
Figure 2-12
Figure 2- 13
Figure 2-14
Figure 2.15
Figure 2- I6
Figure 2- I7
Figure 2-18
Figure 2- I9
Figure 2-20
Figure 2-21
Figure 2-22
Figure 2-23
Figure 2-24
Operation
Model 7072 Installation
Card Connectors..
Connector Configuration..
Triax
Triaxial
General
Model
Model
Model
Model 590 CV Analyzer Connections
Model
Typical
Equivalent Circuit
Model
Connecting Three
Jumper Connector Locations
Three Cards in Daisy Chain Configuration
I6 x 36 Matrix Constructed by External Jumpering.
Using Triax
Power Line
Eliminating Ground Loops
Shielding Example
Dual Shield Test Fixture
Guarded Circuit
Typical Guarded Signal Connections
Cable Preparation ..........................................................................................................................
Instrument Connections..
617 Electrometer Connections..
196 DMM Connections
230 Voltage Source
220 Current Source Connections..
Test Fixture Connections..
7072 Matrix Organization
Tee Adapters to
Ground Loops..
.........................................................................................................................................
..............................................................................................................................
........................................................................................................................................
.................................................................................................................
...............................................................................................................
.....................................................................................................
.................................................................................................................
Connections ..................................................................................................
......................................................................................................
.................................................................................................
...........................................................................................................
of Test Fixture
Cards for 8
....................................................................................................................................
...........................................................................................................................
Connections .......................................................................................
.............................................................................................................
x 36 Matrix.. .............................................................................................
....................................................................................................................
...............................................................................................
Daisy Chain Cards..
......................................................................................................................
........................................................................................................................
.......................................................................................................
....................................................................................
2-2
2-3
2-4
2-5
2-6
2-1 1
2-13
2-14
2-l 5
2-16
2-17
2-18
2-19
2-21
2-21
2-22
................................................................................
2-23
2-24
2-25
2-25
2-27
2-27
2-28
2-29
3 Applications
Figure 3- 1
Figure 3-2
Figure 3-3
Figure 3-4
Figure 3-S
Figure 3-6
Figure 3-7
Figure 3-8
Figure 3-9
Figure 3-10
Figure 3-l I
Figure 3-12
Figure 3- 13
Stand Alone
Computerized CV
Typical Quasistatic CV Curve Generated by Model 595
Typical
Semiconductor Test Matrix
System Configuration
Typical Common-Source
Resistivity Test Configuration
Resistivity Measurement Conventions
Semiconductor Parameter Analysis
SPA Connections
System Configuration for JFET Test
Typical JFET Plot
CV System Configuration..
System Configuration
High-frequency CV
......................................................................................................................................
.....................................................................................................................................
....................................................................................................
...................................................................................................
............................................................................
Curve Generated by Model 590..
.........................................................................................................................
for Measuring Common-Emitter Characteristics..
IV Characteristics..
FET
..................................................................................................................
......................................................................................................
Switching System
........................................................................................................
....................................................................................
.................................................................. 3-6
..................................................
............................................................................ 3-13
3-2
3-3
3-5
3-7
3-8
3-9
3-10
3-l 1
3-14
3-l 6
3-17
Y
4
Service Information
Figure 4-l
Figure 4-2
Figure 4-3
Figure 4-4
Figure 4-5
Figure 4-6
Figure 4-7
Figure 4-X
Figure 4-9
Figure 4.10
5
Figure 5-l
Figure 5-2
Figure 5-2
Figure 5-2
Figure 5-2
Test Cable Preparation ................................................................................................................................
Connecting the Test Cable to the Model 7072
Offset Verification Test Connections..
Connections for Path Isolation Verification
Triaxial Cable Preparation ...........................................................................................................................
Connections for Path Resistance Verification..
Shorting Measurement Paths Using Triax Tee Adapter..
ID Data Timing.. ........................................................................................................................................
Model 7072 Block Diagram ......................................................................................................................
Model 7072 Rear Shield ............................................................................................................................
........................................................................................................
............................................................................................
................................................................................................
...........................................................................................
............................................................................
4-2
4-3
4-4
4-h
4-7
4-X
4-9
4-I I
4.12
4.14
Replaceable Parts
Model 7072 Component Location Drawing, Dwg. No. 7072- 100
Model 7072 Schematic Diagram, Dwg.
Model 7072 Schematic Diagram, Dwg.
Model 7072 Schematic Diagram, Dwg.
Model 7072 Schematic Diagram, Dwg. No. 7072-l 06 4 of 4..
No. 7072-106 1 of 4.. ....................................................................
No. 7072.106 2 014.. ....................................................................
No. 7072-106 3 of 4.. ................... ........................................
..................................................................
...............................................................
5-5
S-7
S-9
.... .5-l 1
S- I3
vi
List of Tables
2
Table 2-l
Table 2-2
Table 2-3
3
Table 3. I
Table 3-2
Table 3.3
4
Table 4. I
Tahlc 4-2
Tahlc 4-3
5
Table 5-l
Table 5-2
Operation
Recommended Cables and Adapters..
Parts for Special Triaxial Cable
Column Numhcring by Slot and Unit
...................................................................................................................
.........................................................................................................
........................................................................................................
.2-4
2-S
2-l 8
Applications
CV Test Crosspoint Summary
Crosspoint Summary Ibr Resistivity Measurements..
Crosspoint Summary for JFET Test
.....................................................................................................................
...........................................................................................................
................................................................................
3-4
3- I2
3 I5
Service Information
Recommended Vcritication Equipment..
Recommended Troubleshooting Equipment
Troubleshooting Procedure
........................................................................................................................
.....................................................................................................
..............................................................................................
4-2
4-10
4 -I I
Replaceable Parts
Model 7072 Electrical Parts List .,,,,,.,,,,,,,.._.__,.........................,................................................................... 5-3
Model 7072, Mechanical Parts List .,......_._._................................................................................................ 5-4
vii
SECTION 1
General Information
1.1 INTRODUCTION
This section contains general information about the Model
7072 Semiconductor Matrix Card. The Model 7072 is
designed for flexibility in switching semiconductor test
setups. Two low-current pathways, and two C-V pathways
in addition to four general-purpose pathways allow complete system versatility.
Section 1 is arranged in the following manner:
1.2 Features
1.3 Warranty Information
1.4 Manual Addenda
1.5
Safety Symbols and Terms
1.6 Specifications
-
1.7 Unpacking and Inspection
1.8 Repacking for Shipment
1.9 Optional Accessories
1.10 Coaxial Jumper Access
tion. When returning the matrix card for repair, be sure
to fill out and include the service form at the back of this
manual in order to provide the repair facility with the
necessary information.
1.4 MANUAL ADDENDA
Any improvements or changes concerning the matrix card
or manual will be explained in an addendum included
with the the unit. Be sure to note these changes and incorporate them into the manual before using or servicing
the unit.
1.5 SAFETY SYMBOLS AND TERMS
The following symbols and terms may be found on an instrument or used in this manual.
The A symbol on an instrument indicates that the user
should refer to the operating instructions located in the
instruction manual.
1.2 FEATURES
symbol on an instrument shows that high
WARNING
CAUTION
heading used in this manual explains
heading used in this manual explains
Key features of the Model 7072 Semiconductor Matrix Card
include:
l 8 x 12 (eight row by 12 column) switching matrix.
l Two rows (A and B) with low-current offset for low-
current measurements.
l Two dedicated rows (G and H) for CV measurements.
l Three-lug triax connectors for all row and columns allow
guarding of each signal pathway to minimize the effects
of stray capacitance, leakage current, and leakage
resistance.
l Model 7072 cards can be connected together to expand
the number of columns in the matrix.
The&
voltage may be present on the terminal(s). Use standard
safety precautions to avoid personal contact with these
voltages.
The
dangers that might result in personal injury or death.
Always read the associated information very carefully
before performing the indicated procedure.
The
hazards that could damage the matrix card. Such damage
may invalidate the warranty.
1.3 WARRANTY INFORMATION
Warranty information is located on the inside front cover
of this instruction manual. Should your Model 71372 require
warranty service, contact the Keithley representative or
authorized repair facility in your area for further informa-
1.6 SPECIFICATIONS
Model 7072 specifications may be found at the front of this
manual. These specifications are exclusive of the matrix
mainframe specifications, which are located in the Model
707 Instruction Manual.
l-l
I
GENERAL INFORMATION
1.7 UNPACKING AND INSPECTION
l Write ATTENTION REPAIR DEPARTMENT on the ship-
ping label.
l Fill out and include the service form located at the back
1.7.1 Inspection for Damage
Upon receiving the Model 7072, carefully unpack it from
its shipping carton and inspect the card for any obvious
signs of physical damage. Report any such damage to the
shipping agent immediately. Save the original packing carton for possible future reshipment.
of this manual.
1.9 OPTIONAL ACCESSORIES
The following accessories are available to make connections to the Model 7072.
Model 61713~slot Male to 2-lug Female Triaxial Adapters-
1.7.2 Shipment Contents
The following items are included with every Model 7072
order:
The Model 6l7I allows male 2.lug triaxial cables to be connected to the Model 7072.
Model 7078-TRX-T 3-Lug Trim Tee Adapter-The Model
7078-TRX-T allows multiple trim connections to the Model
7072 column or row jacks.
l Model 7072 Semiconductor Matrix Card.
l Model 7072 Instruction Manual.
l Coaxial jumper cables (4) for matrix expansion.
l Additional Accessories as ordered.
Model 707%TRX-BNC 3-Lug Triax to BNC Adapter-The
Model 7078~TRX-BNC allows BNC cables to be connected
to the Model 7072.
Model 7078-m Triaxial Cables-The Model 7078-TRX
1.7.3 Instruction Manual
cables are terminated with 3-slot male triaxial connectors.
The Model 7078-TRX-3 is 0.9m (3 ft.) in length, and the
Model 7078-TRx-10 is 3m (10 ft.) long.
-
The Model 7072 Instruction Manual is three-hole drilled
so that it can be added to the three-ring binder of the
Model 707 Switching Matrix Instruction Manual. After
removing the plastic wrapping, place the manual in the
Model 7078-TBC 3-Lug Female Trim Bulkhead Connector
with Cap-The Model 7U78-TBC can be used for applica-
tions such as test fixtures.
binder after the mainframe instruction manual. Note that
a manual identification tab is included and should precede
the matrix card instruction manual.
Model 7U78-CSHP Cable Set--The Model 707%CSHP Cable
Set includes the necessary cables and adapters to connect
the Model 7072 to the Hewlett-Packard Model 4145
Semiconductor Parameter Analyzer. The Model
If an additional instruction manual is required, order the
manual package, Keithley part number 7072-901-00. The
manual package includes an instruction manual and any
707%CSHP includes four Model 7078.TRX-10 loft. 3-lug
triaxial cables, four Model 7051-10 loft. BNC cables, and
four Model 7078-TRX-BNC 3-lug triax to BNC adapters.
pertinent addenda.
1.8 REPACKING FOR SHIPMENT
Should it become necesary to return the Model 7072 for
repair, carefully pack the card in its original packing car-
ton or the equivalent, and include the following
information:
l Advise as to the warranty status of the matrix card.
l-2
1.10 COAXIAL JUMPER ACCESS
Coaxial jumpers can be installed to expand rows A, B, G
and H of the matrix using two or more Model 7072 Cards.
An access door on the mainframe allows access to these
jumpers. To allow access when the Model 7W is mounted
in a rack, it is recommended that the Model 7079 Slide Rack
Mount Kit be used.
I
SECTION 2
Operation
2.1 INTRODUCTION
This section contains information on matrix card connections, installation and matrix programming, and is arranged as follows:
Handling Precautions: Discusses precautions that
2.2
should be taken when handling the card to avoid contamination that could degrade performance.
Dirt build-up over a period of time is another possible
source of contamination. To avoid this problem, operate
the mainframe and matrix card only in a clean environment. If contamination is suspected,clean the card as
discussed in Section 4. Also, the performance verification
procedures in Section 4 can be used to test the card for
low leakage resistances that could signal contamination.
2.3 ENVIRONMENTAL CONSIDERATIONS
2.3
Environmental Considerations: Outlines environmental aspects of using the Model 7072.
2.4
Card Installation and Removal: Details installation
in and removal from the Model 707 Switching Matrix
mainframe.
Connections: Discusses card connectors, cables and
-
2.5
adapters, and typical connections to other instrumentation.
Matrix Configuration: Discusses the switching
2.6
matrix, as well as matrix expansion by connecting two
or more cards together.
2.7
Measurement Considerations: Reviews a number of
considerations when making low-level current and
capacitance measurements.
HANDLING PRECAUTIONS
2.2
To maintain high impedance isolation, care should be
taken when handling the matrix card to avoid contamination from such foreign materials as body oils. Such contamination can substantially lower leakage resistances,
degrading performance. The areas of the card that are most
sensitive to contamination are those associated with the
Teflon@ insulators. To avoid any possible contamination,
always grasp the card by the handle or the card edges. Do
not touch board surfaces, components, or card edge
connectors.
For rated performance, the card should be operated within
the temperature and humidity limits given in the specifica-
tions at the front of this manual. Note that current offset
and path isolation values are specified within a lower range
of limits than the general operating environment.
2.4 CARD INSTALLATION AND REMOVAL
Before making connections, the Model 7072 should be in-
stalled within the Model 707 Switching Matrix, as sum-
marized below. Figure 2-l shows the installation procedure.
WARNING
Turn off the mainframe power and disconnect
the line cord before installlng or removing
matrix cards.
NOTE
The SMB coaxial jumpers used to expand the
matrix with two or more Model 7072 cards need
not be installed before card insertion; an access
door on top of the mainframe allows access to the
SMB connectors after the card is installed.
-
2-l
I
OPERATION
MOUNTING SCREWS
-
CARD HANDLE
Figure 2-1. Model 7072 InstallatiOt’I
2-2
I
I
OPERATION
1. Before installing the card, make sure the access door on
top of the Model 707 is fully closed and secured. The
access door contains tracks for the card slots and must
be in place to properly install the card.
the inner shield is GUARD, and the outer shield, or shell
is chassis ground. Note that 3-lug connectors are used to
avoid possible damage from inadvertently attempting to
connect BNC cables.
2. With one hand grasping the handle, and the other
holding the bottom of the card, line up the card with
the tracks in the desired slot. Make certain that the component side of the card is facing the fan on the
mainframe.
CAUTION CAUTION
Do not touch the card surfaces or any com- Do not touch the card surfaces or any components to avoid contamination that could ponents to avoid contamination that could
degrade card performance. degrade card performance.
3. Slide the card into the mainframe until it is properly
seated in the edge connectors at the back of the slot.
Once the card is properly seated, secure it to the main-
A-H
LOW - current
Rows
3
Mounilng
screw
-Columns
i-12
@j,
@)2
B@
@3
frame by finger tightening the spring-loaded screws.
@4
WARNING
The mounting screws must be secured to ensure a proper chassis ground connection be-
@5
tween the card and the mainframe. Failure to
-
properly secure this ground connection may
result in personal injury or death due to elec-
tric shock.
carrying
Handle
@6
4. To remove a card, first turn off the power and disconnect the line cord from the mainframe. Disconnect all
external and internal cables (internal cables can be
reached through the access door). Loosen the mounting
screws, then pull the card out of the mainframe by the
handle. When the back edge of the card clears the main-
frame, support it by grasping the bottom edge near the
back edge.
2.5 CONNECTIONS
Card connectors, recommended cables and adapters, and
typical connections to test instruments are discussed in the
following paragraphs.
2.5.1 Card Connectors
The card connectors are shown in Figure 2-2. Each row and
column is equipped with a 3-lug female triax connector.
As shown in Figure 2-3, the center conductor is SIGNAL,
Mountlng
SCPW
Figure 2-2. Card Connectors
2-3
I
I
OPERATION
Table 2-1. Recommended Cables and Adapters
Chassis
Ground
Warning : Do not Exceed Maximum
Voltage Levels Shown
Figure 2-3. Triax Connector Configuration
Description
6171
3-slot male to 2-lug
female triax.
6011 2-slot triax to alliga-
tor cable*
7078-TRX-3, 7078TRX-10
triax cables
7078.TRX-T triax tee
adapter
7078TRX-BNC triax to
BNC adapter
7025 unterminated triax
(2
slot)
Guarded
*Model 6171 adapter required to connect these cables to
Model 7072
**6167 requires modification by disconnecting input LO
internally.
adapter (6167**)
Applications
Connect 2.slot triax cable
to 7072
7072 input/output
connections
7072 input/output
connections
Daisy chain 7072 columns
or rows
Connect BNC cables to
7072
For custom 7072
connections
Guarded current source
WARNING
Do
-
not exceed 200V
GUARD, or between SIGNAL and chassis
ground, or GUARD and chassis ground.
between SIGNAL and
2.5.3 Triaxial to Banana Plug Adapter
Preparation
The Model 7072 has 12 columns that are labelled 1 through
12, as well as eight rows, A through H. Rows A and B are
labelled LOW I and are intended for low-current measurements. Rows G and H are labelled CV and are designed
for capacitance-voltage measurements. Rows C through F
are general purpose rows that can be used for ordinary
voltage, current, or resistance measurements.
2.5.2 Recommended Cables and Adapters
Table 2-l summarizes the cables and adapters recommended for use with the Model 7072. Equivalent user-supplied
items may be substituted as long as they are of sufficient
quality (low offset current, high leakage resistance). Using
substandard cables and adapters may degrade the integrity
of the measurements made using the matrix card. See
paragraph 2.7 for a discussion of measurement considerations.
For instruments that use banana jacks, a special 3-slot hiaxto-single banana plug must be prepared, as discussed
below. This special cable can be prepared as outlined below
using the parts listed in Table 2-2. Note that you can use
either an unterminated triax cable, or cut a dual-connector
cable (7L?78-TRX-10) in half to construct two cables. The steps
for the procedure below are shown in Figure 2-4.
1. Using a knife, cut and strip back the outer insulation
about 1% inches.
2. Remove the outer insulation, then cut away the outer
shield back as far as the insulation is stripped.
3. Carefully strip away the insulation over the inner shield
one inch, then cut the inner shield off even with the
stripped insulation.
4. Strip the inner conductor % inch, then twist the strands
together.
5. Unscrew the cover from a banana plug, then slide the
cover over the center conductor of the t&xx cable.
6. Insert the stripped center conductor through the hole
in the body of the banana plug, then wrap the wire
around the plug body.
7. Screw on the plastic cover, and make certain the wire
is secure by gently pulling on the plug.
2-4
I
OPERATION
Table 2-2. Parts for Special Triaxial Cable
Keithley Part or
Model Number
7078-TRX-3 triax
CIA
r
le- l”4
(A) Cut off insulation with knife.
Cut off outer shield.
Insulation Over
Inner Shield
/-
I
cot
2.5.4 General Instrument Connections
The following paragraphs discuss connecting the
Model 7072 to various general classes of instrumentation
such as DMMs, electrometers, sources, and source/measure
units. Because these configurations arc generic in nature,
some modification of the connecting schemes may be necessary for your particular instrumentation. Also, special
cables or adapters may be necessary. In all cases, 3-lug triax
cables must be used to make the connections.
WARNING
Do not use coaxial cables and adapters
because hazardous voltage from guard
sources may be present on the cable shields.
Figure 2-5 shows the general instrument connections for the
discussions below. Note that DUT guarding or shielding are
not indicated here; see Figures 2-21 and 2-24 for shielding
and guarding information. Also, 2-pole switching for rows
A-F is shown in the figures; GUARD is not switched on
rows G and H. As shown, all figures assume instruments are
connected to rows, and the DUT is connected to columns.
(B) Strip insulation off Inner shield.
(C) Twist inner shield then strip Inner conductor.
Twist inner shield and center conductor together,
slip on plastic cover.
(D) Insert wires into hole and wrap around body.
(E) Screw on plastic cover.
Figure 2-4. Triaxial Cable Preparation
DMM Connections
General DMM connections are shown in Figure 2-5(A),
(B), and (C). Floating connections are shown in (A), with
LO and HI routed to two separate jacks on the Model 7072.
The common LO connections in (B) should be used only for
non-critical applications because the performance of the
GUARD pathway is not specified.
WARNING
Hazardous voltage from other guard sources
may be present on LO or the DUT if other
crosspoints are closed.
4-wire DMM connections are shown in Figure 2-5(C). In
this case, a total of fourjacks are required; HI, LO, SENSE
HI, and SENSE LO.
Electrometer Connections
Typical electrometer connections are shown in Figure
2-5(D) through (G). The unguarded volts connections in(D)
show the HI signal path routed through one jack, and the LO
path goes through the other connector. Both GUARD pathways are connected to electrometer LO. For guarded voltage (E), Model 7072 GUARD is connected to electrometer
GUARD.
2-5
OPERATION
I
The connections for electrometer fast amps and resistance
measurements are shown in Figures 2-5(F) and (G). These
configurations are essentially the same as those discussed
GUARD is again connected to source LO, with source HI
and Ix) routed through two pathways. In the case of the
guarded current source in (J), card GUARD of the HI signal
above. For the case of fast amps, both GUARD paths are path is connected to source GUARD, and the other
connected to electrometer Lo, while in the case of guarded
GUARD path is connected to source Lo.
resistance, one GUARD path is connected to electrometer
GUARD, and the other GUARD path is connected to elec-
trometer LO.
Source/Measure Unit Connections
Figure 2-5(J) shows typical connections for a
Source Connections
source/measure unit (SMLJ). In this instance, a remote-
sensing type of a SMU is shown, requiring a total of four
Voltage and current source connections are shown in
Figures 2-5(H) through (J). The HI and LO paths of the
voltage source (H) are routed through two jacks, with both
card GUARD pathways connected to voltage source Lo.
signal pathways to the DUT. For critial measurements, both
source and sense HI pathways would be guarded as
shown, with two of the four card GUARD pathways con-
netted to SMU GUARD terminals. As with other instru-
For the unzuarded current source connections (I), card ment connections, the LO card GUARD pathways are con-
netted to SMU LO terminals.
2-6
A.) DMM Floating
ROW
Warning : Hazardous voltage from guard
source6 may be present on LO.
B.) DMM Common LO
Figure 2-5. General Instrument Connections (A-B)
L----J
L-----f
7072
7072
COLUMN
L-l
Note : Use this configuration only fol
non-crltlcaf measurements.
OPERATION
C.) DMM 4-Wire
ROWS
ROWS
COLUMNS
DUT
L-----l
7072
COLUMNS
r----i
HI
LO
I
Electrometer
D.) Electrometer, Unguarded Volts
Figure 2-5. General Instrument Connections (C-D)
DUT
7072
2-7
I
OPERATION
ROWS COLUMNS
l
E.) Electrometer. Guarded Volts
i-
7072
i r----~ c
ROWS
IIY I
DUT
-0LUMNS
-
2-8
L----A
F.) Electrometer. Fast Current
7072
ROWS
Electrometer
G.) Electrometer. Resistance (Guarded)
Figure 2-5. General Instrument Connections (E-G)
7072
DUT
I
H.) Voltage Source
OPERATION
L-----l
7072
ROWS
I.) Current Source, Unguarded
COLUMNS
L----J
7072
ROWS COLUMNS
DUT
7072
Figure 2-5. General instrument Connections (HJ)
I
2-9
OPERATION
I
K.) Sourca/Measure Unit
ROWS
COLUMNS
-“; /J-F-
L----A
7072
Notes : 1.) DUT shielding/guarding not shown. See figures 2-21 and2-24.
2.) 2-P& switching for rows A-F shown. GUARD is not switched
on rows G and Ii.
Figure 2-5. General Instrument Connections (K)
Z-10
1
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