Specific Process Knowledge/Characterization/Stress measurement

Stress measurements of a thin film can be done measuring the wafer bow before and after deposition of the film. If the film is deposited on both sides of the wafer you can measure the bow after deposition and after removing the film from one of the sides.

The procedure is as follows:

When deposition on one side of the wafer:

1. Measure the wafer bow on one of the profilometers (Tencor or Dektak 8). Save the measurement. It is a good idea to measure across most of the wafer in two directions perpendicular to each other.
2. Deposite the thin film
3. Measure the wafer bow again one the same profilometers as used for the pre-measurement with the same recipe.
4. Measure the thickness of the substrate
5. Measure the thickness of the thin film (ex. using the FilmTek or the Ellipsometer is possible).
6. Use the program for stress measurement in the profilometer software on the profilometer you used for the measurements. Use both the pre-stress measurement and the post-stress measurement.