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On‐line state and parameter Identification of positive photoresist development
Author(s) -
Carroll Thomas A.,
Ramirez W. Fred
Publication year - 1990
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690360711
Subject(s) - photolithography , kalman filter , computer science , line (geometry) , estimation theory , process (computing) , identification (biology) , development (topology) , noise (video) , algorithm , mathematics , artificial intelligence , optics , image (mathematics) , physics , geometry , botany , biology , operating system , mathematical analysis
The development phase of the optical photolithography process has long been considered the most crucial, as it is the final image‐forming step. Process monitoring methods have focused primarily on end point detection and have not used other inferable on‐line information. This paper examines the use of mathematical models in conjunction with on‐line development penetration data to determine process changes. An on‐line sequential parameter identification scheme is used to calculate a current rate parameter value for the development model, and a Kalman filter is used to reduce erroneous observations caused by measurement noise. A powerful development monitor system results from the combination of real‐time data, and on‐line parameter and state estimation theory.