Novel ultra-high sensitive 'metal resist' for EUV lithography

Abstract

This study describes the use of a novel ultra-high sensitive ‘metal resist’ for use in extreme ultraviolet (EUV) lithography. Herein, the development of a metal resist has been studied for improving the sensitivity when using metal-containing non-chemically amplified resist materials; such materials are metal-containing organic–inorganic hybrid compounds and are referred to as EUVL Infrastructure Development Center, Inc. (EIDEC) standard metal EUV resist (ESMR). The novel metal resist’s ultra-high sensitivity has previously been investigated for use with electron beam (EB) lithography. The first demonstration of ESMR performance was presented in SPIE2015, where it was shown to achieve 17-nm lines with 1.5 mJ/cm2: equivalent in EUV lithography tool. The sensitivity of ESMR using EUV open-flame exposure was also observed to have the same high sensitivity as that when using EB lithography tool. Therefore, ESMR has been confirmed to have the potential of being used as an ultra-high sensitive EUV resist material. The metal-containing organic–inorganic hybrid compounds and the resist formulations were investigated by measuring their sensitivity and line-width roughness (LWR) improvement. Furthermore, new processing conditions, such as new development and rinse procedures, are an extremely effective way of improving lithographic performance. In addition, the optimal dry-etching selective conditions between the metal resist and spin-on carbon (SOC) were obtained. The etched SOC pattern was successfully constructed from a stacked film of metal resist and SOC.