Critical dimension control using development end point detection for wafers with multilayer structures

Abstract

Fiber optic based reflectivity measurement during spray or spray/puddje development is effective for accurate critical dimension(CD) control However,there are some difficulties in using wafers with multilayer structures. This paper describes an improved method for end point detection of wafers with multilayer structures which consist of 160+/-lOnin SiN/2Onm Si02 /Si. The improvement has been done in the following way.