A statistical approach to identify semiconductor process equipment related yield problems

Identifying and eliminating yield limiting factors is a critical requirement for achieving accelerated yield improvement rates. This paper presents a systematic methodology for identifying yield problems caused by manufacturing equipment in a semiconductor process. The method uses Multiple Die Yield Analysis methodology to decompose the probe yield into two major components: a non-random systematic yield Y_s , and a random yield Y_r. Systematic or random yield loss problems caused by process equipment are identified based on the analysis of the statistical significance on Y_s and Y_r between the highest yield equipment and all other equipment in the same process step. Applications of the proposed analysis method to many manufacturing lines´ data have been very successful in identifying process equipment related yield problems