Setup

Log on the tool using the LabAccess Terminal
1. This tool is not reservable on Coral
Power up the tool
1. Turn on the lamp power and the lamp ignition located on the M-2000DI (the top black box)
2. The EC-400 should be on at all times
3. The computer monitor should be on at all times.
[Note that the software should always be open. If it is not, you can try to start it, or find a tech]
If the software isn’t open, double click WVASE32TM icon on the desktop.
1. Six windows appear: Model, Generate Data, Fit, Experimental Data, Hardware and Graph.
Click anywhere in the Hardware window and click Initialize. The WVASE32 Hardware log window appears.
Enter a user name and click Ok.
Place sample on stage. Make sure that the light:
1. is aligned with the aperture in the Output unit (MQD-160). [I don’t know how to check this. I guess if the light isn’t anywhere between the two arms of the instrument. Use a piece of paper to find the light. If you can’t find it, get a tech. Never try to mess with any tool’s internals.]
2. is focused on the sample. This can be done by placing a piece of paper on the sample stage to locate the light and aligning the sample with it.
Turn the vacuum on. The switch is located on the lower left hand side of the Sample Stage.
On the Setup menu, select Load Samples. [Need to confirm this is where to click]
The Mount Sample window will appear. Click Ok. A window will appear with a red cross in the middle.
1. There should be grey bars on the window near center. If there are not, find a Tech.
2. If there are not techs, you can try to align the stage so the grey bars show up, using the two knobs located on the front and the right sides of the Sample stage. I don’t know how to do this.
Center the Cross at the origin using the two knobs located on the front and the right sides of the Sample stage. Press “Esc” on the keyboard when the red cross is close to the center
1. Press Esc as soon as it is super close to center.
2. The “Hardware Sample Z-axis alignment” window appears and a graph will be drawn on a different window.
The error message "Insufficient intensity for Auto Alignment of Sample Z-stage" might appear. In this case, repeat steps 6 through 10 again to align the sample better.
When "Repeat tilt-alignment and Z-alignment?" window appears, Select "Yes" to repeat the alignment process and do step 10 again.
1. When the red cross is sufficiently close to the center, select "No" to "Repeat tilt-alignment and Z-alignment?" inquiry.
2. Align the sample [at least] three times (rule of thumb)
Right click on the hardware window, select the Acquire data menu select Spectroscopic Scan. The "V.A.S.E Scan" window appears. Choose range and increment of angles. Typical values for different materials are listed below. Click OK after setting the required values.
1. Metal, dielectrics: 60 to 75 degrees, increment=5°.
2. Silicon: 40 to 55 degrees, increment=5°.
3. "Revs/meas" box can be set to 10 (40 for better precision).
Select Yes/No to the "Save experimental data?" inquiry. Select "No" if you plan to save the model for this sample. If "Yes" is selected, save the data in the "DAT" folder.
Build model for the sample
1. Click anywhere on the "Model" window.
2. Select Add layer. A window appears, highlight the material of interest from the list and click OK. The Layer window will appear. Enter the desired thickness, select fit and click OK. If the selected material is Silicon, 1mm is a typical thickness value and the “fit” option is not active.
3. Add another layer by repeating step 15b.
Click anywhere in the “Generate data” window and select Generate data from the menu.
Click anywhere in the "Fit" window. Select Normal Fits/Normal fit from the menu.
1. In the fit window we have MSE (Mean square error). We want a number less than 10.
2. There will be a thickness guess [in at least one window, check which]
3. If the MSE is greater than 10 or the thickness is not good enough:
  1. Right click on fit and select optical constant fit. Do another fit and the curves approach each other.
  2. Can alter guess for layer thickness and rescan (see Step 13).
To change the wavelength range, left-click generated data. Go to the top bar and click range select.
To save the environment, Click on "Global" on the upper right hand corner of the desktop and select "Save current environment" from the dropdown list. Select the folder you want to save the environment. [I’m not sure what this is for, unless it saves your model and data.]
Unload or swap your sample/s when done.
Log out of the tool using the LabAccess Terminal