Monitoring the Etch Rate of a Constantly Changing Reflective Surface
Original Publication Date: 1978-Apr-01
Included in the Prior Art Database: 2005-Feb-20
The present apparatus involves a simple expedient for etch rate monitoring of a constantly changing reflective surface, i.e., a semiconductor surface being processed either by etching or by deposition. A mirror is placed in a fixed position with respect to the surface. Thus, in effect, we have a two-mirror structure, with the changing surface being the mirror which is constantly changing in distance from the fixed mirror. This change in distance will result in a directly proportional lateral change in the position of a reference point on the changing "mirror" with respect to a fixed point on the fixed mirror. This lateral change may be easily monitored and translated into the etch rate.