AVS 46th International Symposium
    Plasma Science and Technology Division Thursday Sessions
       Session PS1-ThA

Paper PS1-ThA7
DUV Resist Degradation and Surface Roughening under Plasma Exposure

Thursday, October 28, 1999, 4:00 pm, Room 612

Session: High Fidelity Pattern Transfer
Presenter: W.H. Yan, Microelectronic Division, IBM Corp.
Authors: W.H. Yan, Microelectronic Division, IBM Corp.
W. Moreau, IBM Corp.
R. Wise, IBM Corp.
Y. Cui, IBM Corp.
Correspondent: Click to Email
This study investigate the plasma etch characteristic of several different types of DUV photoresist. It has been established that these photoresists suffer from degradation under exposure to common etch processes. We have demonstrated that resist degradation and surface roughening depend on resist polymer composition and etching process conditions. Results from this study clearly indicated: (1) Acrylate component in the polymer breakdown via chain scission during etching. That polymer breakdown causes resist surface pitting. (2) Ion bombardments, etch gas radicals, atoms and polymer deposition from etching reaction in the etching chamber further roughen the resist surface. (3) Heat and UV light in the etching chamber, on the other hand, crosslink resist polymer. The degree of crosslinking highly depends on resist polymer composition. We also investigated UV hardening, E-beam treatment as well as their impacts on resist etch resistance and surface roughening. Results showed that these treatments improve resist etch resistance, but not surface roughness. SEM and AFM were used to study resist surface and sidewall roughness. Gel Permeation Chromatography (GPC) was employed to analyze resist reaction under plasma exposure. The mechanism of resist roughness and its dependence on resist composition was discussed.