Crystalline-Si/SiO2/Si wafer

• Assume that crystalline-Si/SiO2/Si wafer was measured.
• Tip:
  1. Crystalline Si over SiO2 on Si (thickness unknown).
  2. Start by using reference n and k for all layers.
  3. Don’t forget surface oxide!!
  4. Bonus: Try Global fitting thickness.

1. Build up the model layers

1. AddLayer "si_jaw.mat" as the substrate in the Model window.

2. AddLayer "sio2_jaw.mat" as the tabulated SiO2 layer in the Model window. Check a fit box of thickness.

3. AddLayer "si_jaw.mat" again as the tabulated crystalline-Si layer in the Model window.

4. The following dialog box appears. Click "Yes".

• Note: When the same name of model layer is input, this message appears.

5. Check a fit box of thickness in the coupled layer window.

6. AddLayer "sio2.mat" again as the tabulated SiO2 layer, which is an oxide layer on a-Si, in the Model window.

7. Click "Yes" in the message box.

8. Check a fit box of thickness in the coupled layer window.

9. Adjust the thicknesses of SiO2 and crystalline-Si layers close to the graph curves.

2. Normal Fit

1. Do Normal fit in the Fit window, to fit the thicknesses only.

2. The MSE is 21.91.

3. Point-by-point fitting

1. Open the "Edit Parms" dialog box in the Fit window.

2. Click the "Delete All Parms" button.

3. Open the "1 SiO2_jaw" layer window.

4. Check fit boxes of n and k in the "Opt Const Fit" box.

5. Click "OK".

6. Do Point-by-point fitting in the Fit window.

7. The result is shown below. The MSE is improved to be 2.828.