A blog on the repair, operation and calibration of surface analysis systems and components including electron spectrometers, sputter ion guns and vacuum related hardware. Click on the Index tab below to see a list of all posts. Visit our website at http://www.rbdinstruments.com
Longer lifetime ionizer for the 04-303 and 06-350 ion source.
Longer-lifetime-ionizer
As many of you know, RBD Instruments’ 04-303 and 06-350 ionizer rebuilds last for an average of 1100 hours of run time. Depending on how much sputtering you do, that can translate into anywhere from 2 months to 3 years between ionizer replacements. But wouldn’t it be nice if they could last longer, such as 2000 hours or more?
Introducing the new long life 04-303 and long life 06-350 ionizer! There are two failure mechanisms related to the ionizers that we have addressed with our new and improved rebuild process. First, as part of the normal operation of the filament, tungsten slowly evaporates onto the base of the ionizer. That coating can cause leakage current between the grid and extractor that shows up as pressure on the 11-065 controller even when no gas is being fed into the source. That ghost pressure current typically shows up towards the end of the filament lifetime cycle. We have addressed this problem by cutting a groove into the ceramic base at the location where the tungsten deposit occurs. That groove will prevent the leakage current from happening when the deposition occurs.
The second improvement that we have implemented is a special low temperature filament wire. Besides running much cooler, the wire evaporation rate is greatly reduced so the deposition rate is also reduced proportionally. Just as with our normal ionizer rebuilds, the filament will hold its shape for the entire filament lifetime, resulting in a very stable and repeatable ion current.
Another benefit of our low temperature wire is that it takes much less filament current to get the same emission current as compared to the normal tungsten wire. As a result, the ion gun controller will also run 20% cooler and operate trouble free longer.
So how long with our new ionizer last? We are projecting between 2000 and 2500 hours but need more data to be able to provide an accurate answer. That is where you can help us. We will be offering a few of our new long-life ionizers at a reduced price and in return we ask that you keep a log of how many hours you get before the ionizer burns out. As that data comes in we will be able to provide an accurate average lifetime.
A longer lifetime ionizer pays for itself by reducing how often you need to vent your chamber for maintenance.
Below are the DR11 commands use in the 20-622 calibration procedure. The 20-622 electron gun control is used on the Physical Electronics 660 scanning auger systems.
Command Structure
Use DR11 program or RBD 147 diagnostics for computer control.
Function Command/Data (hex)
Beam Voltage 1ddd
Emission 2ddd
Objective Lens 3ddd
Iso. Objective Lens 4ddd
Obj Y 5ddd
Obj X 6ddd
Cond Y 7ddd
Cond X 8ddd
Reset Overcurrent 9ddd
Cond Lens Addd
Notes: – the command and the data are combined in a 16 bit word
– the left-most digit is most significant in address position and data value
Take the readings from the High Voltage (HV) Programming connector on the back panel. The Beam Voltage reading is taken from pin A and the Emission reading is taken from pin B. The reference is to chassis ground. Note: the bit number in () indicates the only bit set (=1), for troubleshooting purposes.
Command/Data BV ctrl voltage (V)
1000H .001
1100H (bit 8) .625
1200H (bit 9) 1.25
1400H (bit 10) 2.50
1800H (bit 11) 5.00
1C00H 7.50
1FFFH 10.00
Check for increasing voltage as you enter the following values in sequence: 1000H, 100FH (bits 0-3), 1010H (bit 4), 1020H (bit 5), 1040H (bit 6), 1080H (bit 7).
Command/Data Emission ctrl voltage (V)
2000H .001
2100H (bit 8) .625
2200H (bit 9) 1.25
2400H (bit 10) 2.50
2800H (bit 11) 5.00
2C00H 7.50
2FFFH 10.00
Check for increasing voltage as you enter the following values in sequence: 2000H, 200FH (bits 0-3), 2010H (bit 4), 2020H (bit 5), 2040H (bit 6), 2080H (bit 7).
Condenser and Objective Lenses
A 200 ohm 2W 10-turn potentiometer must be connected to the Objective Fine Adjustment connector on the back before checking the voltages (Unless it is connected in the electronics bay) . Connect pin D to the pot wiper and connect pins A and C to the pot limits (either order). Set the pot to midway (5 turns for a 10-turn pot).
Note: the bit number in () indicates the only bit set (=1), for troubleshooting purposes. The voltages across the resistors (RX) are taken behind the front panel.
Iso. Objective
Command/Data R1-R6 Voltage (V)
4000H .016
4100H (bit 8) .304
4200H (bit 9) .610
4400H (bit 10) 1.22
4600H 1.83
4800H (bit 11) 2.44
4A00H 3.05
4C00H 3.66
4F00H 4.58
4FFFH 4.88
Check for increasing voltage as you enter the following values in sequence: 4000H, 400FH (bits 0-3), 4010H (bit 4), 4020H (bit 5), 4040H (bit 6), 4080H (bit 7).
Objective
Command/Data R7-R10 Voltage (V)
3000H .021
3100H (bit 8) .322
3200H (bit 9) .645
3400H (bit 10) 1.29
3600H 1.94
3800H (bit 11) 2.58
3A00H 3.23
3C00H 3.88
3F00H 4.85
3FFFH 5.17
Check for increasing voltage as you enter the following values in sequence: 3000H, 300FH (bits 0-3), 3010H (bit 4), 3020H (bit 5), 3040H (bit 6), 3080H (bit 7).
Condenser
Command/Data R11-R14 Voltage (V)
A000H .018
A100H (bit 8) .469
A200H (bit 9) .939
A400H (bit 10) 1.88
A600H 2.82
A800H (bit 11) 3.76
AA00H 4.70
AC00H 5.64
AF00H 7.05
AFFFH 7.50
Check for increasing voltage as you enter the following values in sequence: A000H, A00FH (bits 0-3), A010H (bit 4), A020H (bit 5), A040H (bit 6), A080H (bit 7).
Steering
Check for proper centering of the voltages at the Objective and Condenser Steering connector on the back panel.
Command/Data Between pins, Voltage (V)
57FFH F&H, 0V +/- .4V Obj. Y
67FFH E&G, 0V +/- .4V Obj. X
77FFH B&D, 0V +/- .4V Cond. Y
87FFH A&C, 0V +/- .4V Cond. X
20-622 System Test
It is possible for a 20-620 or 20-622 to work on the bench but not focus properly on a system. That is because on the bench the Objective and ISO Objective supplies are tested separately but on the system the objective coil is actually two coils which are tied together. So one of the objective supplies may cave in when connected to the objective coil. You can do a quick test by measuring the voltage across the current resistors behind the front panel of the 20-622 or 20-620.
Voltages for the 20-622 are listed below. The 20-620 should show a similar trend.
20-622 3kV Beam voltage, COND set to 35%, OBJ set to 74.49%, and Objective fine pot set to midrange.
COND
.856
OBJ
3.68
ISO OBJ
3.69
20-622 5kV Beam voltage, COND set to 35%, OBJ set to 83.49%, and Objective fine pot set to midrange.
COND
1.076
OBJ
3.85
ISO OBJ
3.47
20-622 Coil voltage supply test points
There are three coil voltage supplies in the 20-622:
Condenser 30V DC
Objective 34.5V DC
Isolated Objective 40V DC
To measure the supplies, remove the 4 screws on the 20-622 front panel and drop the front panel down (it is on a hinge).
There are three fuses visible on the front center of the heat sink assembly.
The top fuse is the Condenser supply, and it has a value of 1.5A slow blow. Measure from either side of the fuse to the chassis and there should be approximately 30 V DC when the 20-622 main power is turned ON.
The center fuse is the Objective supply, and it has a value of 2A slow blow. Measure from either side of the fuse to the chassis and there should be approximately 34.5 V DC when the 20-622 main power is turned ON.
The bottom fuse is the isolated Objective supply, and it has a value of 2.5A slow blow. Measure from either side of the fuse to the ISO Objective test point (white wire) near the far-right hand current sense resistors. There be approximately 40 V DC when the 20-622 main power is turned ON.
The picture below shows the ISO Objective test point location.
ISO obj test point 20-622Lens voltage supplies schematic
As many of you may know, RBD Instruments has been providing repair services and parts for old Physical Electronics (PHI) surface analysis systems and components for over 26 years. In fact, some of the electronic and optic units that we work on are over 45 years old!
As a result of aging electronic components in some of the very old units, or a lack of demand, we are discontinuing service on some PHI electronics and optics.
Where possible, in the list below we will offer newer alternative units as replacements. We will also offer technical support if you want to try and repair the unit yourself. With our pricing model that has a cap on the maximum labor charge for electronics and optics it is not economically viable for us to repair these really old units. And if we were to charge the actual time that it may take to repair them, then that would not make fiscal sense for you as it may be less expensive to replace it with a newer unit.
The good news is that RBD Instruments still provides repair services and parts for most older PHI surface analysis systems and components.
Here is the list of obsolete PHI units:
Electronics:
96 V/F preamplifier (We still work on the 96A and 96B)
11-010 Electron gun control (Gray faced units, we still work on the Brown faced units)
11-055 analyzer control
11-500 Analyzer control (Gray faced units, we still work on the Brown faced units)
