AVS 53rd International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS1-WeM

Paper PS1-WeM4
Modifications of Advanced Photoresist Polymers after Plasma Processing

Wednesday, November 15, 2006, 9:00 am, Room 2009

Session: Plasma-Surface Interactions II
Presenter: S. Engelmann, Univ. of Maryland College Park
Authors: S. Engelmann, Univ. of Maryland College Park
R.L. Bruce, Univ. of Maryland College Park
B.F. Smith, Univ. of Maryland College Park
T. Kwon, Univ. of Maryland College Park
R. Phaneuf, Univ. of Maryland College Park
G.S. Oehrlein, Univ. of Maryland College Park
C. Andes, Rohm & Haas Electronic Materials
D.B. Graves, UC, Berkeley
D.G. Nest, UC, Berkeley
M. Goldman, UC, Berkeley
E.A. Hudson, Lam Research Corp.
P. Lazzeri, ITC-irst, Center for Sci. and Tech. Res., Italy
E. Iacob, ITC-irst, Center for Sci. and Tech. Res., Italy
M. Anderle, ITC-irst, Center for Sci. and Tech. Res., Italy
Correspondent: Click to Email
Plasma based transfer of photoresist patterns onto underlying substrates is basic to micro- and nano-fabrication, but suffers from problems like introduction of surface and line edge roughness in the photoresist/underlying features as a result of plasma processing. In this collaboration, we seek to develop a deeper understanding of this behavior along with the formulation of design criteria for new photoresist systems. Etch rates, chemical and morphological evolution of fully formulated photoresist systems as well as carefully selected model polymers have been studied using Ellipsometry, Atomic Force Microscopy, Time-of-Flight Secondary Ion Mass Spectrometry and X-Ray Photoelectron Spectroscopy. We find that the polymer structure in the top surface layer is destroyed within the first 2-3 seconds of plasma exposure accompanied by hydrogen-loss and densification. Furthermore we observed a strong correlation between polymer structure, plasma-induced surface chemistry, and morphological evolution of the sample. We also observed that acrylate content improves the etch performance of our materials and that the plasma etching rate and surface roughening of a fully formulated photoresist is essentially the same as that of the polymer backbone of which it consists. Varying the physical properties of the plasma attack can greatly modify these chemical and morphological changes. The role of process chemistries as well as the effect of ion energy or ion/neutral ratio and the effect of materials modifications for selected conditions will be addressed.