Direct measurement of x-ray mask sidewall roughness and its contribution to the overall sidewall roughness of chemically amplified resist features

Abstract

Correlation of atomic force microscopy sidewall roughness measurements with scanning electron microscopy line-edge roughness measurements on chemically amplified resists exposed by x-ray lithography

Effect of thin-film imaging on line edge roughness transfer to underlayers during etch processes

“…This technique had already been applied to the evaluation of factors that contribute to SWR in chemically amplified resists. 4,13 In the present study, this same approach enables the simultaneous calculation of the two-dimensional SWR of the resist, bottom ARC, hardmask, and substrate surfaces. Subsequently, potential correlations that may exist between lateral surfaces after the development step and after the etch process can be determined.…”

“…2,3 Numerous studies during recent years have attempted to isolate and describe the factors that contribute to resist LER. They include the intrinsic edge roughness found on the mask, which can be transferred to the imaging layer, 4 the influence of aerial image contrast, 5,6 stochastic effects arising from shot noise, 7 the formation of polymer aggregates, 8 the extent of acid diffusion, 3,9 the amount of base quencher present in the resist, 10,11 and the interaction of the exposed resist with the developer. 12,13 Historically, lithographers have focused on understanding the origins of resist LER, in most cases without considering the subsequent effect of plasma etch processes on resist and bottom layer roughness.…”

Effect of developer molecular size on roughness of dissolution front in electron-beam resist

“…1 It is essential to elucidate the origin of LER in order to find ways to reduce it. It is known that LER is related to factors involving the lithographic system, such as aerial image profiles, 2-8 shot noise, 9,10 and mask roughness, 2,11 and also to resist materials and their development. Among these factors, resist materials and the development process are very important because they are surely the ultimate origin of LER.…”

A review of line edge roughness and surface nanotexture resulting from patterning processes

“…It takes into account the molecular structure of the photoresist, the photoacid generator presence, its initiation, diffusion and reaction to create deprotected sites as well as the dissolution of the exposed areas using a quasistatic fast dissolution algorithm [32][33][34]. Excellent process simulation and experimental studies have also appeared in the literature for the process effects on LER, such as aerial image contrast [35][36][37], shot noise [38], development process [39][40][41][42][43], lithographic process conditions [44][45][46][47][48], lithographic materials [32,33,[49][50][51][52][55][56][57][58][59] and others. Our simulation results are consistent with these studies.…”