Patent ID: 6593151
Filing Date: 2003-07-15
Classification: H01L

Abstract:
A method of analyzing a control wafer to determine striations on separately processed product wafers comprising:a) producing the control wafer for analyzing striations formed on at least one of the product wafers having an average product PSG thickness, wherein the control wafer comprises: i) a substrate layer; ii) an USG layer deposited directly above the substrate layer; iii) a PSG layer deposited directly on top of the USG layer, the PSG layer having a control thickness greater than about 2500 Ã¥ and greater than the average product PSG thickness; and iv) a boron phosphorus silicate glass (BPSG) layer deposited directly on top of the PSG layer; and b) analyzing the control wafer to detect if a striation is present in the control wafer.