This literature was published years prior to the establishment of Agilent Technologies as a company independent from
Hewlett-Packard and describes products or services now available through Agilent. It may also refer to products/services no
longer supported by Agilent. We regret any inconvenience caused by obsolete information. For the latest information on
Agilent's test and measurement products go to:
www.agilent.com find products
Or in the US, call Agilent Technologies at 1-800-452-4844 (8am-8pm EST)
H428OA Applications
l
capacitance and Conductance With or Without
Constant DC Bias
HP’s 4280A 1MHz C Meter/C-V Plotter can measure and
display capacitance and conductance. A 1 MHz test signal with
level of 1OmVrms or 30mVrms is used.
Internal DC bias ( f 1OOV) can be applied when needed.
4280 Front Panel Displays C,G and DC bias
n Test Floating and Grounded Devices
Both Floating and Grounded devices can be tested. This
is important because wafer probers will have either floating or
grounded chucks. Both configurations are in common use.
n
capacitance and Conductance Using Staircase
Bias Sweep
4280’s built-in + IOOV DC bias supply can be controlled
from the front panel to sweep in staircase fashion. Capacitance
and conductance can be measured at each step.
Deep Level Transcient Spectroscopy
(DL TS) - Example of Pulse Bias Application
DLTS is used to analyze semiconductor imperfections which
effect IC performance. Small imperfection concentrations which
are too small for analysis by C-V techniques can often be analyzed by DLTS.
m Hard Copy Output
C-V and G-V measurements require no external equipment
and are internally synchronized. Results can be output to analog
X-Y recorders or to computers via HP-IB (IEEE 488).
n Capacitance and Conductance vs. Time
(Pulse Bias)
Minority carrier lifetime and surface generation velocity in
MIS structures can be obtained using C-t results. 4280A uses
two different C-t methods depending on measurement resolution required on the time axis.
Delay time is the time between measurements. When delay
time is set to 10 milliseconds or greater, the 4280A will apply
a single pulse to the device under test. Then a BURST of
measurements are made.
START
When delay time is less than 10 milliseconds, an external
pulse generator like HP’s 8112A must be used. The external
pulse generator applies repetitive pulses to the device under
test. The 4280A makes a single measurement after each pulse.
In the SAMPLING MODE, the 4280A provides synchronization
signals to the external pulse generator.
Time (5)
4
STOP
High speed Gt testing and variable supercooled temperature
are major requirements of DLTS test systems. Shown here is
system hardware including HP’s 4280A for Gt testing with
pulses of IOms to 32 set in duration. HP’s 8112A pulse generator is added when pulse duration shorter than 10m set is
required.
DLTS is a high-frequency capacitance transient thermal
scanning method useful for observing a wide variety of traps
in semiconductors. This new technique, aimed at studying these
centers, uses the capacitance of a p-n junction or Schottky bar-
rier as a probe to monitor the changes in the charge state of
the centers. Complete Gt characteristics are obtained at multiple supercooled temperatures.
Real devices have multiple trap levels and different trap
concentrations. Resulting DLTS curve has multiple peaks as
shown below.
Temperature (deg C)
Important parameters which can be derived from DLTS in-
clude: 1) surface state density, 2) trap concentration, 3) energy
level of traps, and 4) trap capture cross section.
Advantages offered by HP’s 4280A are to expand the range
of analysis to shallower energy levels by offering resolution to
1 O,us when synchronized to an external pulse generator like HP’s
8112A.
HP’S 4280A Offers New Measurement C;
R6
MC,
Tc
M
VC
S
n
FC
(2‘
S.,
Wntroduction
Hewlett-Packard’s Model 4280A 1 MHz C Meter/C-V
Plotter offers new measurement capability and flexibility
for the design and production of IC’s. Benefits are im-
proved IC quality and improved engineering productivity.
HP’s 4280A has capability previously requiring the
following complicated test set up: 1) capacitancelconductance meter, 2) function generator, and 3) computer for
test synchronization.
New measurement capability is featured in transient
C-t measurements with 10 microsecond resolution. Such
testing is used to analyze deep level impurity concentrations which effect IC performance. Transient C-t resolution of 10 microseconds is up to 1000 times better than
ever before available. 4280A features 10ms C-t resolution using internal pulse generator. Add HP 8112A pulse
generator or equivalent to achieve 10,~s resolution.
Convenience features include the ability to test both
floating and grounded devices. Also 428OA’s has capability to compensate a wide range of stray impedances. This
helps eliminate the effect of test fixture residuals.
OFFn nON
cl
:42V = MAXA UNKNOWN
&OATlNG
26
meni
Func
Th
millis
parer
MC
2
W
W428OA Front Panel
Features
1 HP-IB - Construct Your Own System
Standard on 4280A, HP-IB can help you construct an automatic
system. Such systems are used in applications ranging from
materials research, device R&D, process engineering, wafer production and quality assurance.
2 Residual Compensation and Capacitance Offset
Compensate test fixture residuals including up to 5 meters of standard cable (HP P/N 81204195). Also use with Option 001 when off-
setting large values of capacitance to obtain extra digit of resolution on 100pFllnF ranges.
3 Capacitance Digital Display
Standard capacitance display resolution will be 3% digits or 4%
digits depending on test conditions. Option 001 features 5% digit
capacitance resolution using capacitance offset function. This
display also can show deviation.
4 Wide Capacitance Measurement Range
Capacitance measurement range is from 0.001 pF to 1 .QOOOnF.
5 Conductance Digital Display
Standard conductance display resolution will be 3% digits or 4%
digits depending on test conditions. This display also shows
deviation.
6 Wide Conductance Measurement Range
Conductance measurement range is from 0.01~5 to 12.000mS.
7 DC Bias and Time Display
DC bias parameters in volts or time in seconds is displayed depen-
ding on operating mode.
8
Wide Range of DC Bias and Time
DC bias can be varied in + IOOV range. Bias can be 1) constant,
2) staircase sweep (C/G-V) or 3) pulsed (C/G-t).
V-t display shows values of voltage staircase sweep parameters
in C/G-V modes. These parameters include hold time, and step delay
time. V-t display also shows C/G-t parameters like delay time.
9
Enter Numedc Values of Voltage and Time
After selecting bias and time parameters and keying in numeric
values, this key enters value into 4280A memory.
10 Numeric Data Ready to Enter
This LED must be lit before numeric sweep parameter can be
entered.
11 Sweep StartLStop
Start/Stop key controls DC bias and time sweep output. V output
LED lights when bias voltage is applied.
12 Se/act Sweep Parameter or Constant DC Bias
Use up/down keys to select constant DC bias voltage or time sweep
parameter. Enter numeric values using numeric keys.
13
Select Bias Mod&Limit Output Voltage%ld Range
Multi function key selects DC bias mode. Also allows entry of DC
bias voltage limit from numeric keys and acts as Range Hold key.
14 Dispfay Deviation, Percent or Deviation Percent
Perform math operations and display results on C/G displays.
15 Change Number of Display D&its
Reduce number of display counts to less than 1000. Use before
X-Y recording
16 Setup X-Y Recorder
Analog output voltage represents C/G display counts and DC
bias/time sweep. Establish origin and size of X-Y plotting area.
MC
i
Note
ME.
A
tc
Prir
3
Loading...