Yanwen J Fei

US Patent:

20050074908, Apr 7, 2005

Filed:

Oct 8, 2004

Appl. No.:

10/492513

Inventors:

Dennis Ciplickas - San Jose CA, US
Brian Stine - Santa Clara CA, US
Yanwen Fei - Fairfax VA, US

International Classification:

H01L021/66
H01L023/58
H01L029/10
H01L021/44

US Classification:

438014000, 438015000, 438017000, 257048000

Abstract:

A test structure comprising a test pattern is formed on a substrate. The test pattern includes a first comb structure having a plurality of tines, and a second structure. The second structure may be a snake structure having a plurality of side walls or a second comb structure having a plurality of side walls. The tines of the first comb structure are positioned within side walls of the snake structure or second comb structure. The tines of the first comb structure are offset from a center of the side walls. 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.