Dielectric characteristics of low-permittivity silicate using electron beam direct patterning for intermetal dielectric applications

Direct patterning of nonphotosensitive low-k hydrogen silsesquioxane (HSQ) was achieved using electron beam (EB) lithography. The smallest feature size of 60 nm for damascene lines was demonstrated without using etch-stop layer, photoresist, and dry-etching technologies. The probability of low-k degradation can be thereby avoided during these pattern transfer processes. Material analysis including FTIR and TDS have confirmed the explanation, certainly indicating that relatively high intensity of Si-H bonds and low content of moisture were present in the electron-beam-exposed silicate.