TEST STRUCTURES AND MODELS FOR ESTIMATING THE YIELD IMPACT OF DISHING AND/OR VOIDS

摘要

A test structure comprising a test pattern (400) is formed on a substrate. The test pattern (400) includes a first comb structure (401) having a plurality of tines (402), and a second structure (405). The second structure (405) may be a snake structure having a plurality of side walls (406a, 406b) or a second comb structure having a plurality of side walls. The tines (402) of the first comb structure are positioned within side walls (406a, 406b) of the snake structure (405) or second comb structure. The tines (402) of the first comb structure (401) are offset from a center of the side walls (406a, 406b). Test data collected from the test structure are analyzed, to estimate product yield. The test structure may have a lower layer pattern, such that topographical variations of the lower layer pattern propagate to an upper layer pattern of the test structure.