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Study on fabrication process parameter estimation by visual measurement
Author(s) -
Takagi Yuji,
Nakagaki Ryo,
Shishido Chie,
Tanaka Maki
Publication year - 2009
Publication title -
electronics and communications in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.131
H-Index - 13
eISSN - 1942-9541
pISSN - 1942-9533
DOI - 10.1002/ecj.10153
Subject(s) - photoresist , photolithography , critical dimension , process (computing) , focus (optics) , position (finance) , fabrication , resist , depth of focus (tectonics) , process control , materials science , stepper , computer science , optoelectronics , nanotechnology , optics , physics , medicine , paleontology , alternative medicine , subduction , finance , layer (electronics) , pathology , biology , economics , tectonics , operating system
Abstract The cross‐sectional dimensions of the photoresist in the photolithography process are estimated from top‐down scanning electron micrographs for improved control of photolithography conditions. As semiconductor design rules shrink, strict process control is becoming increasingly important. Two primary process parameters in the photolithography process, exposure dose and focus position, require strict control in order to achieve the desired photoresist profile. The relationship between the photoresist profile and changes in these two parameters of photolithography is determined by simulation, and features suitable for estimation of the photoresist profile are identified in conventional images obtained for critical dimension monitoring. Experimental results demonstrate that process parameters can be estimated to within error of 1.0 mJ/cm 2 for exposure dose and 80 nm for focus position, making the proposed method suitable for photolithography process control. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(8): 11–17, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/ecj.10153