Novel flowable CVD process technology for sub-20nm interlayer dielectrics

Abstract

Flowable CVD (Chemical Vapor Deposition) process having merits in terms of both superior gap-fill performance of SOD (Spin-on Dielectric) and process stability of CVD was introduced for the interlayer dielectric (ILD) in sub-20nm devices based on new concept and precursor. Remote plasma during low temperature deposition and ozone treatment was adopted to stabilize the film. We also developed a novel Flowable CVD process which does not oxidize Si or electrode, resulted in removal of Si3N4 stopper layer as an oxidation or diffusion barrier. After the application of Flowable CVD to 20nm DRAM ILD, we could reduce not only loading capacitance of Bit-line by 15% but also enhance comparable productivity. Through the successful development of sub-20nm DRAM ILD Gap-fill process, Flowable CVD was successful demonstrated as a promising candidate for mass production-worthy ILD in sub-20nm next generation devices.