Characteristics of Silicon-Based Negative Resists in ArF Excimer Laser Lithography.

Abstract

Bi-level resist systems consisting of a thin top silicon containing resist and a thick bottom layer are very promising with ArF-excimer laser lithography for obtaining high-aspect patterns on a high-step substrate. We studied the 193 nm light sensitivity and the crosslinking mechanism of various crosslinking-type functional groups by molecular orbital (MO) calculations. We found that negative siloxane resists with suitable functional groups like chloromethylphenyl exhibit very high sensitivity without using a chemically amplified system, due to the high oscillator strength with many allowed 7t-1t* transitions caused by 193 nm irradiation. No profile deformation by excessive absorption is observed in the resist systems, due to the high 02-RIB resistive thin imaging resist layer. A 0.14 µm line and space pattern can be delineated at a dose of 7 mJ/cm2 using three-dimensional polysilphenylenesiloxane (TSPS) / novolak bi-level resist systems.

Photoimaging Materials Based on Base-amplifying Silicone Resins Having Phenylsulfonylethyl Groups

“…The siloxane skeleton as a polymer main chain is expected to enhance a plasma-etching resistance when these polymers are applied to photoresist materials [5]. First, it should suppress the excessive diffusion of amine molecules proliferated from base amplifiers.…”