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Simultaneous optimal bottom linewidth and side‐wall curvature control of wet etching
Author(s) -
Zhou Bo,
Ramirez W. Fred
Publication year - 1996
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.690420918
Subject(s) - microelectronics , laser linewidth , curvature , etching (microfabrication) , fabrication , optimal control , materials science , control theory (sociology) , engineering , mechanical engineering , control (management) , computer science , optoelectronics , nanotechnology , optics , mathematics , physics , mathematical optimization , geometry , medicine , laser , alternative medicine , layer (electronics) , pathology , artificial intelligence
Etching is one of the critical steps in the fabrication of microelectronics devices. A time‐optimal control problem with a dual‐term terminal cost including both bottom linewidth and side‐wall curvature is formulated to implement an optimal open‐width design principle. A singular‐arc solution does not exist and the control action is bangbang. The optimal switching time is analytically calculated. The feasibility and effectiveness of this technique are illustrated by simulation studies. This design and control philosophy can easily be applied to other microelectronics manufacturing processes.