8 September 2017 Gradient-based optimization for efficient exposure planning in maskless lithography
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Scanning laser lithography is a maskless method for exposing photoresist during semiconductor manufacturing. In this method, the energy of a focused beam is controlled while scanning the beam or substrate. With a positive photoresist material, areas that receive an exposure dosage over the threshold energy are dissolved during development. The surface dosage is related to the exposure profile by a convolution and nonlinear function, so the optimal exposure profile is nontrivial. A gradient-based optimization method for determining an optimal exposure profile, given the desired pattern and models of the beam profile and photochemistry, is described. This approach is more numerically efficient than optimal barrier-function-based methods but provides near-identical results. This is demonstrated through simulation and experimental lithography.
© 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)
Omid T. Ghalehbeygi, Omid T. Ghalehbeygi, Adrian G. Wills, Adrian G. Wills, Ben S. Routley, Ben S. Routley, Andrew J. Fleming, Andrew J. Fleming, } "Gradient-based optimization for efficient exposure planning in maskless lithography," Journal of Micro/Nanolithography, MEMS, and MOEMS 16(3), 033507 (8 September 2017). https://doi.org/10.1117/1.JMM.16.3.033507 . Submission: Received: 22 May 2017; Accepted: 9 August 2017
Received: 22 May 2017; Accepted: 9 August 2017; Published: 8 September 2017

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