Greetings.
You may be able to use the services of a metrology company like Thermawave
(Model = optiprobe) or Tencor (UV1260?).

Depending on the thickness of your films, you should be able to do
multi-layer measurements with good goodness of fit.

Goodluck.
Jaideep


At 01:17 AM 4/15/99 PDT, jae hong LIM wrote:
>hi!
>i wanna know the depth of layers.
>i have 4 multi layer(silicon dioxide, silicon nitride, poly-silicon,
>silicon nitride) wafer. but i don't know the way to measure the depth
>of each layer during etching.
>but i can't make a step.
>because right now i can't use dry etch.
>so i wanna use an ellipsometer.
>if you have info about it let me know.
>thanks in advance.
>