Novel hardening methods of DUV chemically amplified photoresist by ion implantation and its application to new organic ARC material and bilayer process

摘要

Abstract: In the experiment, various ion species are implanted tothe developed images to improve etching and thermalflow resistance of Deep UV chemically amplifiedresists. Among various ion species, it is found thatArgon ion did not affect the photoresist thickness andcritical dimension after ion implantation. Muchimproved results could be obtained. Untreated contacthole patterns start flowing on 120 degrees C andfinally are filled up on 130 degrees C with noticeablefilm shrinkage. On the other hand, Argon implantedcontact hole patterns are standing still up to 170degrees C without any thickness shrinkage and CDvariation. Application of higher temperature results inthe protrusions at the bottom of the resist profiles.Pattern deformation after dry etching process can beprevented. Cross-sectional SEM micrographs of the ionimplanted contact hole patterns show clear interfacebetween the hardened and the unhardened. SIMS analysisof the ion implanted photoresists reveal the presenceof the ions at the surface of the substrate, not in theresist. Detailed mechanistic study will be discussed.Application of this process to bilayer resist processand a new antireflective layer has been tried andevaluated. And also the effects of accelerating energyand ion dose on reflective index of carbonized layerhave been investigated. RI analysis shows the change ofn and k value according to energy and ion dose. It canbe speculated that the transparent matrix resin changedto highly absorbing amorphous carbon based materials.It is quite sure for that the n and k value can becontrolled for the application of bottom antireflectivelayer. This new ARC material is very compatible toresist and est to strip, compared to conventionalOrganic Bottom ARC material. Thickness optimization forthe ARC, application to real device and etchingcharacteristics are under development in our lab. !13