Resist Thickness Dependence of Latent Images in Chemically Amplified Resists Used for Electron Beam Lithography

Abstract

Transistors have been miniaturized to increase their integration. With miniaturization, the thickness of the patterning material, called a resist, has been decreased to prevent them from collapsing. In this study, the resist film thickness dependence of the latent images of chemically amplified electron beam resists was investigated using the simulation on the basis of their sensitization and reaction mechanisms. The decompositions of sensitizers (photoacid generators) were significantly affected by the dynamics of low-energy electrons at the interfaces of resist films. The subsequent deprotection was also affected by the initial acid distribution. Simulation results indicated that such interfacial effects basically increased with the decrease of resist film thickness.