Line‐Profile resist development simulation techniques

Abstract

AbstractThe relative advantages and disadvantages of three different algorithms are compared for simulating the time evolution of two‐dimensional line‐edge profiles produced by a locally rate dependent surface etching phenomenon. Simulated profiles typical of optical projection printing and electron‐beam and X‐ray lithography of micron‐sized lines in resist and etching of ion‐implanted SiO2 are used as a basis of comparison. One of the algorithms is a cell‐by‐cell removal model used earlier by Neureuther and Dill. One of the newly developed algorithms employs ray tracing; it can be shown that the path followed by a point on a front between the developed and undeveloped regions can be calculated using ray‐optic equations. The other new algorithm uses a string of points initially on the surface of the exposed resist. The points on the string advance perpendicular to the local direction of the string; with time the string of points moves down into the resist, replicating the action of a developer. We compare the computing cost, convenience, and accuracy of the algorithms.