50-096 X-ray source control DLL using Windows 10

Posted on May 11, 2020 by Randy

50-096 X-ray source DLL installation and setup for Windows 10

Overview

The 50-096 X-ray source control uses a RS232 serial port to communicate with the PC. AugerScan talks to a Phi 50-096 DLL that in turn communicates with the 50-096. This DLL was originally written for old 32 bit XP PCs and there are some tricks involved with getting it to install and operate correctly on a Windows 10 machine.

Note that the RS232 cable needs to be a straight rough type. Most newer PCs do not have a RS232 port so you will need to get a USB to RS232 adaptor.

The steps involved are as follows:

Copy the 50-096 DLL to the windows/SysWOW64 folder
Register the 50-096 DLL
Set up the Com port

Step 1. Copy the 50-096 DLL to the PC. You can copy it anywhere on the PC, but initially copy it to the AugerScan directory.

Step 2. Register the 50-096 DLL.

Right click on the Start icon and select Command Prompt (Admin). Or if that does not work, search for Command Prompt and Run as Admin
Type cd\Windows\SysWOW64 then press enter
Type regSvr32 Model_50_096.dll and press enter

You should get a message that indicates that the Model_50_096.dll was registered.

Step 3. Set up the com port.

Type Registry Editor in the search box and then run the registry editor as Admin
Go to \\HKEY_Current_USER\Software\ULVAC_PHI\HARDWARE\X_RAY_CONTOL\
Add a new string (which will add a new key)
Name the new key ComPort
Verify the type of key is REG_SZ
Put in the com port number that you are connecting to the 50-096. It needs to be COM (all caps) plus the com port number. So for example, COM3.
The 50-096 operates at 9600 baud with no parity and 8 data bits.

The 50-096 in now ready to operate with AugerScan.

Note: When first turned on, the Model 50-096 X-ray source power supply needs to be programmed to operate at 15 keV. To do this, perform the following steps:

1. Press the Local button under Control Select.

2. Press the Start button for the Water Pump.

3. Press the High Voltage button above the keypad.

4. Press the Display/Enter Setpoints button above the keypad. (LED should light.)

5. Press 1 – 5 – 0 – # on the keypad.

6. Press the remote button under Control Select. The 50-096 will retain the 15 keV setting until it is manually turned off or there is a power interruption.

Once this is set up AugerScan will automatically turn the 50-096 source on and off during and after acquisitions.

Tip: If you program in 12 or 13kV then that is what will be used when the 50-096 is turned on.

Stability testing of surface analysis optics

Posted on March 6, 2020 by Randy

There are two easy ways to check the stability of the electron or photon source on an X-ray photoelectron spectrometer, Auger electron spectrometer or Scanning Electron microscope:

Measure the target current and plot the results vs. time using a data logging picoammeter such as RBD’s 9103.
Acquire a depth profile region over a wide energy range but do not turn on the sputter ion gun.

Method 1 – Plot the target current vs. time.

As shown in the pictures below, plotting the target current versus time shows the stability of the electron beam as well as trends in the current. In this case the current being measured is an electron beam in the range of approximately 300nA.

By changing the scale of the plot, you can see finer details of the current stability and any trend. In this measurement the current drifted up by about 30 nA over a 2 hour period and started to stabilize after the first hour. Room temperature changes can effect the stability of electron optics as can thermal mass of the electron source.

Measuring target current vs. time works well for electron beams on Auger spectrometers and SEMs, as well as secondary electrons generated by X-ray sources on XPS systems. The secondary electron current generated by X-ray sources is directly proportional to the X-ray flux.

Method 2 – Wide energy range depth profile.

For this method you want to set up a region for a depth profile that is at least 1000 eV wide. In the example below we acquired from 1000 to 0 eV on a silver sample, 2 sweeps per cycle. Normally the ion gun is turned on for a depth profile but for this test the ion gun is not turned on.

In the picture below you can see the Profile vs. time display where the highest count in each cycle is displayed.

This picture of all 95 Ag cycles super imposed shows that the stability is pretty good. A depth profile test like this tests not only the X-ray source stability, but also the analyzer voltages, electron multiplier and detector electronics. You can do the same test with an AES system which would test the electron gun as well as the analyzer,electron multiplier and detector electronics.

This picture below shows the first cycle and the next picture shows the last cycle. If you look very closely you will see a small increase in the carbon peak that coincides with the over all slight drop in the intensity of the Ag profile vs. time display. Carbon will typically increase over time in UHV systems due to adsorption and desorption effects.

If you have some extra time you may want to run one of these test methods on your XPS, AES or SEM. The results can be interesting and if nothing else will let you know that your system is stable.

Model 290 Hot/Cold module leakage current

Posted on February 26, 2020 by Randy

The 10-325 specimen stage, which is commonly used on PHI Physical Electronics 5600 through 5800 XPS X-ray photo-electron spectrometer surface analysis systems, is often equipped with the model 290 Hot/Cold module.

The design of the Model 290 Hot/Cold module incorporates some zirconium oxide ceramics to electrically and thermally isolate the specimen holder from the specimen stage. Zirconium oxide has a very low thermal conductivity that is about 10% of the thermal conductivity of the more common alumina (aluminum oxide) ceramic material used on many UHV optics units. Zirconium oxide is a good choice for hot or cold specimen stages.

Over time, though, the evaporation of materials from specimens, as well as the evaporation of the filament on the Model 290, can coat the zirconium oxide ceramics. This coating can cause the specimen sample holder to become resistive to ground, which in turn affects the accuracy of target current measurements. The leakage current of a coated ceramic might be several hundred nano amps. This means that only target currents above that several hundred nano amps value would be measurable. ISS or static SIMS (both options on XPS systems) need the ion current to be set in the range of 1 to 2 nA. And aligning the monochromator requires measuring currents of 3 nA or less. If the specimen stage leakage current is high, then it would be impossible to accurately measure or set those currents.

To test your target leakage current, simply measure the target current using the +90V bias box and picoammeter without any electron, ion, or X-ray source turned on. Typically, the leakage current will be just a few 10s of picoamps. If the leakage current is much higher than low picoamps, the zirconium ceramics shown in the image below may be coated and should be replaced the next time the system is up to air for maintenance.

The replacement procedure is simple.

Vent the chamber and remove the specimen stage.
Place the specimen stage on a workbench with some aluminum foil (UHV foil preferred) so that you can catch parts that will come off the specimen stage while you are working on it.
Remove the end screw and washer and slide out the first long ceramic.
Install a new long ceramic and replace the washer and screw.
Repeat for the other long ceramic.
For the back short ceramic, first remove the bearing by removing the C clamp on the shaft and sliding the shaft out. Note that two thin washers that will come off the bearing shaft as you pull it out.
Next loosen the two pan head slotted screws and slide out the old ceramic and replace it with the new one. Tighten the 2 flat head slotted screws and then replace the bearing.
For the front short ceramic, just loosen the two pan head slotted screws and remove the old ceramic and replace it with the new ceramic. Then tighten the two pan head slotted screws.

After replacing all of the zirconium oxide ceramics, the leakage current should be minimal.

Reinstall the 10-325 specimen stage then pump down and bake out the chamber.

The RBD part number for the set of 4 ceramics is 290CK-4RE. Contact us for more information