P. Argitis et al., ADVANCED EPOXY NOVOLAC RESIST FOR FAST HIGH-RESOLUTION ELECTRON-BEAM LITHOGRAPHY, Journal of vacuum science & technology. B, Microelectronics and nanometer structures processing, measurement and phenomena, 13(6), 1995, pp. 3030-3034
Aspects of the formulation of a highly sensitive cresol epoxy novolac-
based chemically amplified negative resist (epoxy resist, EPR) and opt
imization of critical process parameters for high-resolution electron-
beam lithography are reported. The bulk resist sensitivity (E(80), dos
e for 80% thickness retention) is 0.9 mu C cm(-2) at 40 kV. The effect
of postapply bake and postexposure bake on resist sensitivity, contra
st and resolution are investigated and optimized for lithography up to
the 0.1 mu m regime, The resist process is characterized by a good ex
posure dose latitude and relevant insensitivity to the variation of th
ermal processing conditions. Postexposure bake temperature variations
in the 90-130 degrees C range cause minimal change in sensitivity but
remarkable change in contrast. Due to this behavior the resist process
is not described satisfactorily by the reaction kinetic models common
ly used to characterize chemically amplified resists of different chem
istry. (C) 1995 American Vacuum Society.