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
Category Archives: Operation and Calibration Procedures
Operation and calibration procedures for PHI (Physical Electronics) components
The model 32-100 electron multiplier supply is used on older Physical Electronics Auger electron spectroscopy and X-ray photoelectron spectroscopy surface analysis systems to control the electron multiplier voltage.
When using the 32-100 electron multiplier supply in the digital mode (the software automatically sets the electron multiplier voltage) the auto-ems box in the Auger Scan software AES electron multiplier properties dialog box needs to be checked, and the CMA multiplier switch on the front panel of the 32-100 must be set to digital.
But what if the 32-100 still does not work in the digital mode? In that case, there may be a problem with one of the digital ICs. The following procedure explains how to try and repair this problem.
Turn off the 32-100 and remove the cover.
Most 32-100s have three ICs for the SED digital side of the control which are not used. You can move those ICs over to the CMA side of the control and see if that solves the problem.
Remove ICs U2, U4 and U6. These are the CMA digital ICs. Then, move over U3, U5 and U7 from the SED side if those chips are available. If they are missing, then you will need to order some of those ICs from Digikey, Newark or RBD Instruments. U2 and U4 are 74LS174s and U6 is an AD7521.
If you did have those ICs and that did not solve the problem, then it most likely means that one of the encoder circuit ICs are defective. Those are U16 (74123) and U1 (AM25LS2538). RBD Instruments provides these parts.
You do not need to replace the SED digital ICs as they are not used.
It is assumed that the 32-100 is working in the analog mode. If the 32-100 is not working in the analog mode it will not work in the digital mode either.
Refer to the pictures below for the locations of the ICs on the 32-100 motherboard.
Note that the switch positions need to be set as shown below.
32100-switch-positions
If you need further help troubleshooting your 32-100 electron multiplier supply please contact RBD Instruments dot com
Older PHI scanning auger systems use the model 97 SED preamplifier to obtain secondary electron images. Occasionally you will not be able to get a TV image on your scanning auger system but are not sure what the problem is. This post will explain how to test the 97 SED preamplifier to determine if it is working properly or not.
For purposes of this test, we will run the J3 video output from the 97 SED preamplifier directly to the TV monitor video input. If you have a 660 or 4300 scanning auger system where the image is displayed directly on the PC monitor you can leave the J3 cable connected.
Turn off the 32-100 electron multiplier supply main power. For 660 and 4300 systems, turn off the card rack power.
Disconnect the J1 NEG and J2 POS cables from the 97 SED preamplifier. That will remove the high voltage from the preamplifier and ensure that there is no risk if electrical shock.
Carefully remove the 97 SED preamplifier from the SED feedthrough flange. Hold the 97 SED preamplifier firmly when loosening the screws and lift the preamplifier straight up and off of the SED flange so that you do not risk breaking the ceramic feedthroughs on the SED flange.
Remove the J3 video out cable and connect a BNC cable from J3 video out on the 97 SED preamplifier to the Video In on the back of the TV monitor. If you have a 660 or 4300 scanning auger system, disregard this step.
Note the position of the COL tab on the 97 SED preamplifier as shown in the pictures below.
Turn on the 32-100 electron multiplier supply or card rack power supply.
Make sure that the 32-100 SED voltage is turned to OFF and the SED voltage knob is fully CCW. On 660 or 4300 systems, after going through the turn on sequence set the SED voltage to Zero in the scanning dialog box.
Use a wire or screwdriver and “tickle” the COL tab on the 97 SED preamplifier.
When tickling the 97 SED COL tab you should see a significant amount of noise on the TV monitor. If so, then the 97 SED preamplifier is working properly. There could be contrast or gain issues with the preamplifier that may not show up with this test, but essentially you can rule out the 97 SED preamplifier as the reason that you are not getting a TV image.
Additional information:
On 660 and 4300 systems this test may be inconclusive as the 79-170 or 81-175 scanning electronics may have a problem on the video board. If you do not see noise in the TV dialog box when performing this test then you can monitor the J3 video output on the 97 SED preamplifier and except to see what appears as high frequency noise in the range of 0 to +2V DC when the 97 SED preamplifier COL lead is being tickled.
If the 97 SED preamplifier test passes but you are not getting a TV image there are a few other possibilities.
No TV raster. An easy way to test that is to acquire an elastic peak in the point mode and then turn on the TV with a low magnification. The elastic peak should become jagged if the TV raster is working properly. You can also use an oscilloscope and measure the waveforms on the end of the CMA deflection cable.
No SED voltage. You can use a high voltage probe and measure the voltage between the NEG and POS cables that connect to the 97 SED preamplifier. CAUTION – high voltage is present! Refer this test to qualified personnel who are trained to work with high voltage.
A defective or worn out electron multiplier. If you have a megohmmeter that can measure over 100 Meg ohms (many meters can only measure resistance to 20 Meg ohms) you can measure the resistance between the NEG and POS feedthrough on the SED flange. Typical resistance for a good electron multiplier is 80 to 120 Meg ohms. If the resistance is 150 Meg ohms or higher the electron multiplier should be replaced.
Use care when remounting the 97 SED preamplifier to the SED flange as the SED feedthroughs can be easily broken. Make sure the 32-100 or card rack power supply is OFF when reinstalling the 97 SED preamplifier or cables.
RBD Instruments provides repair services and loaners for the 97 SED preamplifier, and we also provide the electron multipliers. If you need help diagnosing problems your system or parts, please visit our website at rbdinstruments dot com.
This post will explain how to find the analyzer focal point on a PHI 5000 series XPS system and then align the system microscope to that point.
The general idea is that the lens on the SCA (spherical capacitive analyzer) has a very specific focal point where the highest counts, smallest analysis area, and best energy resolution can be obtained. By using a special slotted silver specimen that specific SCA focal point can be located and the system microscope and ion gun are then aligned to that same point. Once this procedure is performed then each time the sample is brought into focus on the microscope TV image the sample will be aligned to the analyzer focal point.
This procedure is written for the Physical Electronics 5000 series XPS instruments, but can be applied to other XPS instruments as well. In addition to this written procedure, there is also a video at this link: Finding the focal point of an XPS system.
slotted-silver-specimen
Concept: The X-ray source illuminates the slotted silver sample and generates an XPS silver spectrum. The lens on the analyzer is set and the sample is moved while looking at the silver peak during a refresh alignment acquisition. By selecting progressively smaller lens areas and moving the sample, you can determine exactly where the focal point of the SCA is for the smallest analysis area.
If your system is equipped with a standard dual anode 15kV X-ray source, use it for the alignment and select it in the software hardware properties dialog box. If your system only has a mono source then you will need to use that as the source. It is more difficult to find the focal point with the mono source as the excitation area produced on the specimen is much smaller than the standard source.
Load the slotted silver sample into the system. It should be mounted on a recessed sample mount. If you do not have a slotted sample mount then use washers to raise the slotted silver specimen up from the sample mount. The slits in the silver specimen should line up with the Y axis of the chamber (parallel with the analyzer lens).
Position the silver sample so that it is about 0.65 inches from the end of the analyzer lens. This is approximately the correct Z height and is a good starting point.
Lightly sputter clean the slotted silver sample with the largest possible raster size (10 mm X 10 mm on most systems).
Set up an alignment acquisition on the silver peak: 375eV upper limit, 365eV lower limit, a high pass energy such as 187.75, eV per step of 1 and a time per step of 30 to 50mS. The pass energy for your system may be different, just use a large one that is about 150 to 200 eV.
Select aperture 3 minimum area in the XPS hardware properties dialog box and also set the analyzer lens knob to 3. That will set the analysis area to 400 µM. Note: This part of the procedure is written for a 5500, 5600 or 5700 XPS system. If you have a 5400 then set the analyzer lens to 2 and select aperture 2 small area. For more information on the lenses for the different PHI analyzers refer to this link: phi-xps-lens-area-information
If using the standard –x-ray source, turn the screw CCW on the X Y Z aligner until the nose of the X-ray source is as close as you can get without blocking the microscope TV image. If using a mono source do not move the source. If necessary, refer to the PHI user manual or contact RBD Instruments for information on how to align the monochromator if you are not sure it is properly aligned.
Start the alignment acquisition and adjust the X and Y on the x-ray source for maximum counts on the 367.8 eV silver peak (standard dual anode source only, do not change any settings on the mono source).
Move the silver specimen until you can determine that you are in the largest slit. When the analyzer lens is looking in the slit the silver peak counts will drop. Move to where you are in the corner of the slit. Since the analysis area on the lens is set to 400 µm and the largest slit is 1000 µm, the counts will drop to essentially zero when you are in the slit, and will come up to some maximum when out of the slit.
Once you are certain that you have determined where the analysis area is on the largest slit, place an erasable mark on the TV monitor at that spot. This is your initial alignment location. You may need to adjust the microscope X and Y to get the image to match where you think you are looking at on the specimen.
Next, move over to the 800 µm slit and confirm that the analysis area is where you think it is. Adjust the spot on the TV monitor if needed.
Move into the 400 µm slit and adjust the Z height for the lowest counts when in the slit. For the 400 µm analysis area setting, the counts will drop by two thirds when in the slit – they will not go to zero. Once you have found the minimum count rate in the 400 µm slit Z height, then move over to the 400 µm hole and fine tune the X, Y and Z positions on the specimen stage for the lowest count rate when inside the hole. That should be about 30% of the maximum signal.
Using the highest zoom on the microscope, adjust the camera focus ring and X Y positions so that the 400 µm hole is centered and in focus on the TV monitor.
Now, we will repeat the procedure using the smallest aperture. In the XPS hardware properties dialog box select lens 1 minimum area. On the analyzer set the lens knob to position 1.
For the 5500, 5600 and 5700 XPS systems, repeat this procedure using the 150 µm slit and hole. For the 5400 XPS systems, repeat this procedure using the 200 µm slit and hole.
Once the focal point as been determined using the 150 µm hole, adjust the microscope focus ring (at the highest zoom), X and Y position so that the hole is centered and in focus. Only the center of the image will be in focus, the edges will be slightly blurred. TIP: Once the camera is in focus and tightened down, gently whack it a few times and see if the image comes back to the exact same place. If not, readjust and re-tighten until it stays in the same place when whacked. If it is not really tight then it may move when the system gets bumped and you will no longer be at the correct focal point. Also, by having it really tight then if you need to remove the microscope for a bake out the X and Y should stay pretty close, this will make the post bake-out alignment check easier.
The key to this alignment is to have a known good silver slotted specimen. Over time the silver coating on the specimen will wear away (from sputter cleaning) and although still coated, the silver may be very thin in some areas. That can give you a false minimum when adjusting the position of the slotted silver sample. RBD Instruments now provides these slotted silver samples for a fraction of what they cost elsewhere. At our low price, you can replace your old slotted silver sample with a known good one. You can get more information on our slotted silver sample at our website or by phoning us at 541 330 0723 X 310. For a limited time, mention this blog post and receive a 25% discount off the purchase price of any slotted silver specimen alignment standard.
