ASTeX AX2100 Installation

MICROWAVE

POWER GENERATOR MODEL AX2100 SERIES

INSTALLATION

AND

OPERATIONS MANUAL

Part No. OM00023

Rev E

July 2001

90 INDUSTRIAL WAY

WILMINGTON, MA. 01887-4610 [phone]

AX2100 Series Microwave Power Generator	Table of Contents

Table of Contents

Contents	Title	Page
		No.
Section 1	Introduction and Specifications
1.1	Description	1-1
1.2	Features	1-1
1.3	Magnetron Power Heads	1-2
1.4	Applications	1-2
1.5	AX2100 Series Microwave Power Generator Specifications	1-4
Section 2	Safety
2.1	Overview	2-1
2.2	Microwave Radiation	2-1
2.2.1	What is Microwave Radiation?	2-1
2.2.2	Microwave Safety	2-2
2.3	Ultraviolet Radiation	2-3
2.3.1	Ultraviolet Radiation Limits	2-3
2.3.2	Ultraviolet Radiation Safety Using Products Manufactured by ASTeX	2-4
2.4	High Voltage	2-5
2.5	Cleaning	2-6
2.6	Safety References	2-6
Section 3	Installation
3.1	Overview	3-1
3.2	Line Voltage	3-1
3.2.1	Model AX2115	3-1
3.2.2	Model AX2110	3-1
3.2.3	Model AX2107	3-1
3.3	Ventilation/Cooling	3-2
3.4	Connection	3-2
3.5	Initial Calibration	3-3
Section 4	Operation
4.1	Controls and Indicators	4-1
4.1.1	Front Panel	4-1
4.1.2	Rear Panel	4-3
4.2	Operating Procedures	4-3
4.2.1	Start-up Procedure for Systems Terminated into a Dummy Load	4-3
4.2.2	Start-up Procedures for Systems without Dummy Load	4-5

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Table of Contents AX2100 Series Microwave Power Generator

Section 5 Theory of Operation
5.1	Overview	5-1
5.2	Magnetron Power Head	5-1
5.3	Power Supply and Control Unit	5-2
5.4	Power Supply and Control Unit Block Diagram	5-2
5.5	Overloads	5-3
5.6	Soft-Start	5-4
5.7	Reflected Power Shutdown	5-4
5.8	Interlocks	5-4
5.9	Reflected Power Measurement	5-4

Section 6	Calibration
6.1	Overview	6-1
6.2	Forward Power	6-1
6.3	Reflected Power	6-2
6.4	Cables	6-5
6.5	Interchanging Magnetron Heads	6-5

Section 7	Remote Control
7.1	Overview	7-1
7.2	Remote Control	7-1
7.3	Reflected Power Shutdown	7-3
7.4	Filament Enable	7-3
7.5	Connector J1 Interface Circuitry	7-4
7.6	Connector J3 Interface Circuitry	7-4
7.7	Modulation	7-4
7.8	Local/Remote Default Startup	7-5

Section 8	Troubleshooting
8.1	Overview	8-1
8.2	No Lights on Front Panel	8-1
8.3	READY Indicator Does Not Light	8-1
8.3.1	Filament Enable LED 5 Illuminated	8-1
8.3.2	Magnetron Power Head LED 5 Illuminated	8-2
8.3.3	Power Supply LED 2 Illuminated	8-2
8.3.4	Bus DC Voltage LED 3 Illuminated	8-3
8.3.5	External Interlock LED 4 Not Illuminated	8-3
8.4	Overload (OVLD) Fault Indicator	8-3
8.4.1	HV DC Output Over Voltage and Over Current Trip	8-4
8.4.2	HV Output Cable Test	8-4
8.4.3	Magnetron Tube Over Temperature Trip	8-4
8.4.4	Reflected Power Trip	8-4
8.5	No Reflected Power Indication	8-4
8.6	Low Output Power	8-5
Appendix	Accessory Hardware	A-1
A

iv	MKS, ASTeX Products

AX2100 Series Microwave Power Generator	List of Illustrations and Tables

List of Illustrations

Figure	Title	Page
No.		No.
1-1	Typical ASTeX Microwave Plasma Setup	1-3
1-2	AX2100 Series Power Supply	1-5
1-3	Air-Cooled Magnetron Power Head	1-6
1-4	Water-cooled Magnetron Power Head	1-7
1-5	AX3120 Circulator with Reflected Power Coupler	1-8
2-1	Selected Exposure Standards	2-2
3-1	Interconnections between Power Supply and Magnetron Power	3-3
	Head
3-2	Magnetron Dip Switch Label	3-3
3-3	Calibration Points	3-4
4-1	Standard Front Panel	4-2
4-2	Remote-Only Option Front Panel	4-3
4-3	Rear Panel Controls and Connectors	4-4
5-1	Power and Control Unit Block Diagram	5-3
6-1	Forward Power Calibration Setup	6-3
6-2	Reflected Power Calibration Setup	6-4
6-3	Reflected Power Calibration Points	6-5
7-1	Connector J1 Interface Circuitry	7-5
7-2	Connector J3 Interface Circuitry	7-6
7-3	Control Board JMP1 Location	7-6
7-4	JMP1 Detail	7-7
8-1	Control Board LED Locations	8-3

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List of Illustrations and Tables	AX2100 Series Microwave Power Generator

List of Tables

Table	Title	Page
No.		No.
1-1	AX2115 Microwave Generator Technical Specifications	1-4
2-1	Relative Spectral Effectiveness by Wavelength	2-5
2-2	Permissible Ultraviolet Exposures	2-5
3-1	Cooling Water Requirements	3-2
4-1	Figure 4-1 Callouts	4-2
4-2	Rear Panel Controls and Indicators	4-3
7-1	Remote Control Signals on Connector J1	7-2
7-2	Remote Control Signals on Connector J3	7-2
7-3	Response Time	7-4
7-4	Typical Modulation Times	7-4
8-1	Troubleshooting, READY LED Not Illuminated	8-2
8-2	Troubleshooting, OVLD Indicator Illuminated	8-6

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AX2100 Series Microwave Power Generator	Introduction and Specifications

Section 1

Introduction and Specifications

1.1Description

This section is a general introduction to the AX2100 Series Microwave Power Generator (AX2100 series). It includes descriptions of major features, types of power heads used, and typical applications.

The AX2100 series includes the following MKS, ASTeX Products models: AX2107 (700W); AX2110 (1000W); AX2115 (1500W). These models differ in their input power requirements identified in table 1-1. The AX2100 series consists of the following components:

∙Power supply

∙Magnetron power head.

∙Control cable

∙HV Cable

∙Reflected power coupler

∙Reflected power cable

Depending on the model, the AX2100 series microwave power generator delivers from 700W to 1500W CW of microwave power at 2.45 GHz, regulated to 0.25% of output power with less than 1% ripple. Simple controls and automatic protective features allow reliable and safe operation in any environment, for both laboratory and production applications.

The power supply, that operates a magnetron power head, contains the switching power supply and control electronics. The high-frequency power supply uses feedback regulation for exceptional output stability and low ripple. Due to its unique design, the AX2100 series is simultaneously small, lightweight, and high-performing.

1.2Features

The AX2100 series is equipped with the following protective features:

∙A power shutdown under high reflected-power conditions with user-selectable setpoint.

∙A power shutdown under over current/voltage conditions.

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Introduction and Specifications	AX2100 Series Microwave Power Generator

∙A power shutdown if the magnetron overheats.

∙The interlock system prohibits the power supply from generating high voltage if the covers are removed, or if the cables are not connected properly. Other features include:

∙Interchangeability of power supplies, remote heads, reflected power diodes and cables.

∙Digital metering of forward and reflected power.

∙Availability of status and control signals to an interface connector.

∙A remote only option (AX2100 series cannot be operated from the front panel).

∙A time meter on the magnetron tube measures magnetron tube life.

∙A time meter on the control board is used to measure power supply operational time.

∙Front panel can be removed without removing AX2100 series from rack to facilitate troubleshooting and repair.

∙Reflected-power diode available on circulator or separate waveguide pieces.

∙Ability to turn off magnetron filament if AX2100 series is idle for long periods of time.

1.3Magnetron Power Heads

The AX2100 series power supply is designed for use with a magnetron power head. The required microwave output power level determines the design details of the power supply.

The magnetron power head is available with air or water cooling. The air-cooled head uses forced air for cooling the magnetron, while the water-cooled head uses water to cool the magnetron (with a small fan in the head enclosure to provide circulation). Therefore, the watercooled head is ideally suited for use in a clean-room environment.

Each magnetron power head include a magnetron, overload sensor, cooling air or water, and waveguide output. In addition, a 9-pin D connector provides an interface to a reflected power detector located on a separately-supplied directional coupler. The AX2100 series uses the signal from this detector to sense reflected power, thus protecting the magnetron tube. This protective feature allows the system to tolerate any load without damage.

1.4Applications

The AX2100 series is typically used in plasma production applications such as ion sources for ion implantation, ion beam milling, ion-assisted deposition, plasma-enhanced chemical vapor deposition, and plasma etching. The output quality and integrated controls make them ideally suited for driving plasma sources, and their small size makes them economically attractive for use in high voltage environments. Other uses include lighting applications such as power sources for microwave discharge lamps, plasma spectroscopy, or gas chromatography. Figure 1-1 shows an example of a plasma system installation.

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AX2100 Series Microwave Power Generator	Introduction and Specifications

	Applicator
Remote-Control
Box
3-Stub Tuner	Circulator
	Dummy Load
	Water-Cooled Magnetron
	Power Head
	Power Supply

Figure 1-1. Typical MKS, ASTeX Products Microwave Plasma Setup

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Introduction and Specifications	AX2100 Series Microwave Power Generator

1.5 AX2100 Series Microwave Power Generator

Specifications

Refer to table 1-1 for the technical specifications for the AX2100 series. Refer to figure 1-2 for an illustration of the power supply. The magnetron power head is shown in figure 1-3. Refer to figure 1-4 for an illustration of the AX3032 circulator.

TABLE 1-1. AX2100 Series Microwave Generator Technical Specifications

Item		Specification
Microwave Power Generator
Power Output (Model AX2115)	0.125 to 1.5 kW CW, adjustable by front-panel
	control or remotely.
Power Output (Model AX2110)	0.125 to 1.0 kW CW, adjustable by front-panel
	control or remotely.
Power Output (Model AX2107)	0.125 to 0.7 kW CW, adjustable by front-panel
	control or remotely.
Frequency	2455 MHz ± 15 MHz
Frequency Stability	Less than 1 MHz long-term drift after initial warmup.
	Less than 2 MHz pulling from 300 W to 1500 W
	output.
Ripple	Less than 1% of output power.
VSWR Allowable	Tolerates any load without damage.
Regulation	0.25% of output power.
Power Input (Model AX2115)	208 V	3φ, 20 A, 50/60 Hz. (20A service) 11A	rms
	current draw at full rated output power.
Power Input (Model AX2110)	208 V	1φ, 20 A, 50/60 Hz. (20A service) 15A	rms
	current draw at full rated output power.
Power Input (Model AX2110)	240 V	1φ, 20 A, 50/60 Hz. (20A service) 11.6A rms
	current draw at full rated output power.
Power Input (Model AX2107)	208 V	1φ, 20 A, 50/60 Hz. (15A service) 11.5A rms
	current draw at full rated output power.
Power Input (Model AX2107)	240 V	1φ, 20 A, 50/60 Hz. (15A service) 8.8A rms
	current draw at full rated output power.
Metering	Digital Metering of forward and reflected power.
Size	7-inches high, 19-inches wide with standard rack
	mountable housing, 19-inches deep, including
	connectors
Weight	Less than 46 lbs.
Magnetron Power Head
Size	12.5-inches long, 7-inches wide, 8 inches high
Weight	Less than 18 lbs.
Waveguide Output	WR284 aluminum with CPR284G flanges
AX3032 Circulator with Reflected Power Coupler
Size	8.4-inches long, 8.7-inches wide, 9.6-inches high
Weight	Less than 18 lbs.
Waveguide Output	WR284 aluminum with CPR 284G flanges.

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AX2100 Series Microwave Power Generator	Introduction and Specifications

CONNECTORS
6.50"		17.00"
				FAN
				19.00"
		19.00"
			AX2115
(Standard front panel)	REFLECTED		FORWARD	7.00"
		WATTS	WATTS
READY	OVID	HV ON	HV OFFPOWER SET
		19.00"
			AX2115
(Remote only option				7.00"
front panel)

Figure 1-2. AX2100 Series Power Supply

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Introduction and Specifications	AX2100 Series Microwave Power Generator

7.50"	12.75"
	11.25"
7.00"
9 .50"
3.00"
	3.00"
	TYP
4 .50"	3.38"
	1.00"
	1.25"

Figure 1-3. Air-Cooled Magnetron Power Head

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AX2100 Series Microwave Power Generator	Introduction and Specifications

5.5	8.4

2.0
1.0	5.4	3.3

3.4 #8-32 x 1/2 DP

MOUNTING HOLES (4)

SHOWN WITH REMOV-

ABLE FEET

0000

8.0

1.5

NOTE: ALL DIMENSIONS

IN INCHES

R4.5 MIN

0.8	3.3
	8.8

Figure 1-4. Water-Cooled Magnetron Power Head

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Introduction and Specifications

AX2100 Series Microwave Power Generator

Figure 1-5. AX3120 Circulator with Reflected Power Coupler

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AX2100 Series Microwave Power Generator	Safety

Section 2

Safety

2.1Overview

This section gives a brief introduction to safety considerations concerning the MKS, ASTeX Products AX2100 series.

2.2Microwave Radiation

2.2.1 What is Microwave Radiation?

Non-ionizing radiation is electromagnetic radiation that does not disrupt the chemical bonds in biological molecules. The electromagnetic frequencies that produce a photon energy of less than 0.1 electron volts, and hence are called non-ionizing, are those frequencies below roughly 1011 MHz. For reference this is just above the ultraviolet frequencies.

The sources of man-made electromagnetic radiation fall into two categories: communication and non-communication. In the communication applications, the sources include AM and FM radio, TV, two-way radio and radar, to name only a few. Examples of non-communication applications are: RF heat sealers and dryers, and industrial processes using microwaves, microwave ovens, and medical diathermy equipment.

Measurements of electromagnetic radiation exposure have become necessary during the past few years due to the proliferation of sources of RF energy, the development of safety standards against which the safety of radiation exposure can be judged, and a continually increasing public awareness and concern over the possibility of health hazards from human exposure to radio waves.

Several Federal agencies are actively engaged in the study of the biological effects of RF fields and the development of protective standards for both susceptible workers and the general population. These government agency programs include the Center for Devices and Radiological Health (CDRH), the National Institute of Occupational Safety and

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Safety	AX2100 Series Microwave Power Generator

Health (NIOSH), various components of the Department of Defense (DOD), and the Environmental Protection Agency (EPA). The EPA has drafted a standard (ANSI/IEEE C95.1- 1992: Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields—3kHz to 300gHz) that specifies Federal regulatory limits applicable to the general population. Figure 2-1 depicts several safety standards for RF exposure.

DENSITY		100	1982 ANSI
						1974 ANSI, OSHA
POWER		10
							CANADA OCCUPATIONAL
EQUIVALENT PLANE WAVE
		1				CANADA GEN. POPULATION
	)
	2
	(MW/CM	.1
		.01				USSR OCCUPATIONAL
						USSR GEN. POPULATION
	.001
		.03	.3	3.0	30	300	3000	30000
				FREQUENCY IN MHz

Figure 2-1. Selected Exposure Standards

2.2.2 Microwave Safety

A leakage check should be performed whenever the system is started and should be specified as a standard operating procedure for operating the system. Set up procedures necessary to meet the requirements of OSHA standard 29-CFR-1910, a copy of which may be obtained from MKS, ASTeX Products on request, would be a place to start if another procedure is not in place.

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AX2100 Series Microwave Power Generator	Safety

A leakage check is particularly important whenever some physical change has been made to the system such as replacing any of the microwave components.

To perform a leakage check, use an approved leakage meter such as the Model HI-1501 manufactured by Holaday Industries, Inc,. 14825 Martin Drive, Eden Prairie, MN 55344 (Tel. [phone]). The HI-1501 is also available as an optional accessory from MKS, ASTeX Products.

To use the meter, place the hand-held probe about one to two inches away from any joint or opening in the AX2100 series external surfaces or the machine interface flange. Observe the reading on the leakage meter as you move the probe around the entire perimeter of the flange or opening.

The AX2100 series is constructed to permit less than 1 mW/cm2 maximum microwave leakage, measured at 5 cm from any point accessible to service personnel. The action needed to fix a leak may be simply tightening a flange. However, in some cases, it may be necessary to replace an entire system component. After your action, start up the system again and repeat the leakage check to verify that there are no leaks.

2.3Ultraviolet Radiation

2.3.1 Ultraviolet Radiation Limits

Ultraviolet radiation is produced by electromagnetic waves in between the visible and X-ray spectrums. The AX2100 series produces a plasma that will generate ultraviolet radiation. In addition, the AX2100 series uses an ultraviolet lamp to assist in plasma starting; both of these are potential sources for ultraviolet radiation exposure. The following tables and data are from the American Conference of Governmental Industrial Hygienists (ISBN: 0-936712-61-9).

These Threshold Limit Values (TLV's) refer to ultraviolet radiation in the spectral region between 200 and 400 nm and represent conditions under which it is believed that nearly all workers may be repeatedly exposed without adverse effect. These values for exposure of the eye or the skin apply to ultraviolet radiation from arcs, gas and vapor discharges, fluorescent and incandescent sources, and solar radiation, but do not apply to ultraviolet lasers. These values do not apply to ultraviolet radiation exposure of photosensitive individuals or of individuals concomitantly exposed to photosensitizing agents. These values should be used as guides in the control of exposure to continuous sources where the exposure duration shall not be less than 0.1 seconds.

These values should be used as guides in the control of exposure to ultraviolet sources and should not be regarded as a fine line between safe and dangerous levels.

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Safety	AX2100 Series Microwave Power Generator

The threshold limit value for occupational exposure to ultraviolet radiation incident upon skin or eye where irradiance values are known and exposure time is controlled is as follows:

For the near ultraviolet spectral region (320 to 400 nm) total irradiance incident upon the unprotected skin or eye should not exceed 1 mW/cm2 for periods greater than 103 seconds (approximately 16 minutes) and for exposure times less than 103 seconds should not exceed one J/cm2.

∙For the actinic ultraviolet spectral region (200-315 nm) radiation exposure incident upon the unprotected skin or eye should not exceed the values given in Table 2-1 within an 8-hour period.

∙To determine the effective irradiance of a broadband source weighted against the peak of the spectral effectiveness curve (270nm), the following weighting formula should be used:

Eeff ≈	E1S1Δλ
where:	monochromatic source at 270nm in W/cm2
Eeff= effective irradiance relative to a
(J/s/cm2)

E1= spectral irradiance in W/cm2/nm

S1= relative spectral effectiveness (unitless) Δλ= bandwidth in nanometers.

∙Permissible exposure time in seconds for exposure to actinic ultraviolet radiation incident upon the unprotected skin or eye may be computed by dividing 0.003 J/cm2

by Eeff inW/cm2. The exposure time may also be determined using Table 2-2 which provides exposure times corresponding to effective irradiances in µW/cm2.

∙All the preceding TLVs for ultraviolet energy apply to sources which subtend an angle less than 80° . Sources which subtend a greater angle need to be measured only over an angle of 80° .

Conditioned (tanned) individuals can tolerate skin exposure in excess of the TLV without erythema effects. However, such conditioning may not protect persons against cancer.

2.3.2 Ultraviolet Radiation Safety Using Products Manufactured by MKS, ASTeX Products

Microwave plasma sources necessarily generate ultraviolet radiation. For safety of operating personnel, ultraviolet attenuating glass such as Pyrex™ should be used for viewports into plasma systems wherever possible. When quartz or sapphire or other ultraviolet transmitting materials must be used, special care should be exercised to ensure that ultraviolet absorbing safety glasses are worn when viewing the plasma. In all cases

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AX2100 Series Microwave Power Generator	Safety

(whatever the window material) exposure time should be minimized. Ultraviolet radiation meters are available and should be used to check any equipment emitting light from a plasma through materials which may transmit ultraviolet.

TABLE 2-1: Relative Spectral Effectiveness by Wavelength

	Wavelength (nm)	TLV (mJ/cm2)	Relative Spectral Effective
			(S1)
	200	100	0.03
	210	40	0.075
	220	25	0.12
	230	16	0.19
	240	10	0.30
	250	7.0	0.43
	254	6.0	0.5
	260	4.6	0.65
	270	3.0	1.0
	280	3.4	0.88
	290	4.7	0.64
	300	10	0.30
	305	50	0.06
	310	200	0.015
	315	1000	0.003

TABLE 2-2: Permissible Ultraviolet Exposures

	Duration of Exposure (Per Day)	Effective Irradiance (Eeff(μW/cm2)
	8 hours	0.1
	4 hours	0.2
	2 hours	0.4
	1 hour	0.8
	30 minutes	1.7
	15 minutes	3.3
	10 minutes	5
	5 minutes	10
	1 minute	50
	30 seconds	100
	10 seconds	300
	1 second	3000
	0.1 second	30,000

2.4High Voltage

During operation, the AX2100 series produces voltages up to 10 kV. These voltages are located inside the inverter module subassembly, the magnetron power head and the

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