Optimal wafer site selection using forward selection component analysis

P. K S Prakash*, B. Honari, A. Johnston, S. F. McLoone

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

18 Citations (Scopus)


Reducing wafer metrology continues to be a major target in semiconductor manufacturing efficiency initiatives due to it being a high cost, non-value added operation that impacts on cycle-time and throughput. However, metrology cannot be eliminated completely given the important role it plays in process monitoring and advanced process control. To achieve the required manufacturing precision, measurements are typically taken at multiple sites across a wafer. The selection of these sites is usually based on a priori knowledge of wafer failure patterns and spatial variability with additional sites added over time in response to process issues. As a result, it is often the case that in mature processes significant redundancy can exist in wafer measurement plans. This paper proposes a novel methodology based on Forward Selection Component Analysis (FSCA) for analyzing historical metrology data in order to determine the minimum set of wafer sites needed for process monitoring. The paper also introduces a virtual metrology (VM) based approach for reconstructing the complete wafer profile from the optimal sites identified by FSCA. The proposed methodology is tested and validated on a wafer manufacturing metrology dataset.

Original languageEnglish
Title of host publicationASMC (Advanced Semiconductor Manufacturing Conference) Proceedings
Number of pages6
Publication statusPublished - 23 Jul 2012
Event2012 23rd Annual SEMI Advanced Semiconductor Manufacturing Conference, ASMC 2012 - NY, Saratoga Springs, United States
Duration: 15 May 201217 May 2012


Conference2012 23rd Annual SEMI Advanced Semiconductor Manufacturing Conference, ASMC 2012
Country/TerritoryUnited States
CitySaratoga Springs


  • forward selection component analysis
  • principal component analysis
  • Virtual Metrology
  • wafer site selection

ASJC Scopus subject areas

  • General Engineering


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