AVS 52nd International Symposium
    Plasma Science and Technology Monday Sessions
       Session PS-MoP

Paper PS-MoP21
Comparison of C@sub 4@F@sub 6@ with C@sub 4@F@sub 8@ Chemistry for Deformation of ArF Photoresist and Silicon Dioxide Etching using Dual Frequency Superimposed (DFS) Capacitive Coupled Plasmas

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Plasma Science and Technology Poster Session
Presenter: C.H. Lee, Sungkyunkwan University, Korea
Authors: C.H. Lee, Sungkyunkwan University, Korea
C.H. Park, Sungkyunkwan University, Korea
N.-E. Lee, Sungkyunkwan University, Korea
Correspondent: Click to Email
As the critical dimension (CD) of advanced CMOS devices is scaled down below 100 nm, 193 nm ArF photoresist (PR) needs to be used as a mask for various etching processes including silicon nitride (SiN) hard-mask opening. Recently, dielectric etch process using ArF photoresist mask by dual frequency superimposed (DFS) capacitive coupled plasma (CCP) has attracted a lot of attention. High frequency (HF) power is used to enhance plasma density and low frequency (LF) power is used to control ion bombardment to the wafer. During dielectrics etch process using DFS-CCP, understanding of ArF photoresist deformation is very important. It has been found that the most serious problems of the hard-mask open process with ArF PR are striation, wiggling, and agglomeration of the PR. In this study, we investigated deformation of ArF photoresists and silicon dioxide etching by varying the process parameters such as HF(13.56, 27.12, and 60 MHz)/LF(2 MHz) power ratio, O@sub 2@ flow, CH@sub 2@F@sub 2@ flow rate and etch chemistry (C@sub 4@F@sub 8@ or C@sub 4@F@sub 6@/ CH@sub 2@F@sub 2@/ O@sub 2@/ Ar). Characterization of surface chemical change was performed by X-ray photoelectron spectroscopy (XPS). Surface morphological changes also investigated by field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). Also, morphological changes of surface and line edges in ArF PR, SiO@sub 2@ etch rate, selectivity over PR during etching of ArF PR/BARC/SiO@sub 2@ structures were investigated. Effects of process parameters on the etch results will be discussed in detail.