The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 14, 2002
Filed:
Mar. 25, 1999
William D. Heavlin, El Granada, CA (US);
Advanced Micro Devices, Inc., Sunnyvale, CA (US);
Abstract
Identification of within-wafer and wafer-to-wafer variations in yield induced by processing steps in a multi-step manufacturing process. Methods are implemented along with wafer position tracking for process control of the manufacturing process. Wafers are systematically rotated according to their position in a batch before entering a processing step. Wafer position tracking analysis of rotated wafers advantageously reveals a static pattern on each wafer regardless of position in a batch. Alternatively, data reduction methods provide a compact representation of site-specific yield data. The data reduction methods use multidimensional scaling to determine distance factor scores and angle factor scores. The distance factor scores track changes in pattern on the wafers. Wafers similar in pattern regardless of rotation angle have similar distance factor scores. The angle factor scores track rotation of patterns on wafers. Analysis of scatter plots enables a process operator to determine which processing step is responsible for variations in yield.