AVS 52nd International Symposium
    Plasma Science and Technology Thursday Sessions
       Session PS-ThM

Paper PS-ThM8
Surface Modification of Photoresists in Electron Beam-Generated Plasma

Thursday, November 3, 2005, 10:40 am, Room 304

Session: Plasma-Surface Interactions II
Presenter: B. Orf, University of Maryland at College Park
Authors: B. Orf, University of Maryland at College Park
G.S. Oehrlein, University of Maryland at College Park
D. Leonhardt, US Naval Research Laboratory
S.G. Walton, US Naval Research Laboratory
Correspondent: Click to Email
An electron beam (e-beam) generated plasma system has been used to study the factors that contribute to plasma-induced surface modifications of UV photoresists. Due to the low electron temperature of e-beam generated plasmas, minimum ion energies are much lower than in RF excited plasma discharges, and can be more accurately controlled in the low energy regime. Thus surface modifications such as roughening, compositional changes, and bond rearrangements (i.e. cross-linking, graphitization) can be studied systemically with respect to the ion energy. In this work we have examined the interaction of Ar and Ar/fluorine plasmas with commercial 193 nm and 248 nm photoresists. Following plasma exposure, the photoresist films were characterized ex situ by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), contact angle measurements and ellipsometry. Ion energy and exposure time were carefully selected to establish the role of ion bombardment in the surface modification, and determining the threshold energies for photoresist damage versus etching. Additionally, the effect of surface relaxation time was investigated by modulating the e-beam generated plasma, to understand how long-lived radicals and the organic material react during the plasma afterglow. The observed differences in behavior of the 193 nm and 248 nm photoresists will be discussed in terms of compositional and structural differences of the materials.