Off-campus UMass Amherst users: To download campus access theses, please use the following link to log into our proxy server with your UMass Amherst user name and password.
Non-UMass Amherst users: Please talk to your librarian about requesting this thesis through interlibrary loan.
Theses that have an embargo placed on them will not be available to anyone until the embargo expires.
Access Type
Open Access
Degree Program
Electrical & Computer Engineering
Degree Type
Master of Science in Electrical and Computer Engineering (M.S.E.C.E.)
Year Degree Awarded
2011
Month Degree Awarded
May
Keywords
aerial image, finite element method, photolithography, electromagnetics, octree, simulation
Abstract
Modern semiconductor manufacturing requires photolithographic printing of subillumination wavelength features in photoresist via electromagnetic energy scattered by complicated photomask designs. This results in aerial images which are subject to constructive and destructive wave interference, as well as electromagnetic resonances in the photomask features. This thesis proposes a 3-D full-wave frequency domain nonconformal Octree mesh based Finite Element Method (OFEM) electromagnetic scattering solver in combination with Fourier Optics to accurately simulate the entire projection photolithography system, from illumination source to final image intensity in the photoresist layer. A rapid 1-irregular octree based geometry model mesher is developed and shown to perform remarkably well compared to a tetrahedral mesher. A special set of nonconformal 1st and 2nd order hierarchal OFEM basis functions is presented, and 1st order numerical results show good performance compared to tetrahedral FEM. Optical and modern photomask phenomenology is examined, including optical proximity correction (OPC) with thick PEC metal layer, and chromeless phase inversion (PI) masks.
First Advisor
Marinos N. Vouvakis
Included in
Electromagnetics and Photonics Commons, Electronic Devices and Semiconductor Manufacturing Commons