MULTI-CHANNEL LASER INTERFEROMETER for PROFILING ETCH-RATE UNIFORMITY ACROSS a SAMPLE
Original Publication Date: 1987-Oct-01
Included in the Prior Art Database: 2005-Feb-02
This article describes a method and apparatus for measuring etch rates simultaneously across the width of a sample in an inline plasma (or down stream from the plasma) etch process. The method involves measuring several points across the width of a substrate to allow real time profiling so that uniformity studies can be performed quickly and in situ . The apparatus design incorporates ease of alignment and eliminates a need for moving parts. This multi-channel laser interferometer profiling method is accomplished by installing an apparatus (Fig 1) onto the system under evaluation. The plasma etch process chamber must have a transparent viewport which would allow the transmission of the wavelengths of the selected laser light.