Photogenerators of Sulfamic Acids; Use in Chemically Amplified Single Layer Resists.

Abstract

A novel material, bis(4-t-butylphenyl)iodonium cyclamate, an alkylaminosulfonate salt capable of photogenerating a zwitterion sulfamic acid is shown to have utility in 248 and 193nm single layer chemically amplified resists. Specifically, bis(4-t-butylphenyl)iodonium cyclamate may be employed as a self-leveled photoacid generator (PAG) in resists in which protecting groups with a low activation energy are present. Alternatively, in resins protected with high activation groups, this material serves the role of a low volatility, low diffusion photodecomposable base used in conjunction with a super-acid PAG. In both types of resists, bis(4-t-butylphenyl)iodomum cyclamate reduces resist line slimming and T-topping by respectively reducing acid diffusion and its depletion at the resist surface. The above mentioned advantages of reduced line slimming and post-exposure bake delay (PED) stability are accomplished both in the case of the low and high activation energy resists without the need for an additional amine component. Finally, formulation of the low activation energy resist with the cyclamate PAG suppresses film thickness loss during exposure thus reducing outgassing off volatiles.