Plasmonic nitridation of SiO_2/Si(100) surface covered with gold nanoparticles via nitrogen plasma-produced radicals and light

摘要

In this work, the optical response of gold nanoparticles was used for radical-induced nitridation of a SiO_2/Si(100) surface. High-quality SiON thin films were successfully formed via radicals and light from a low-temperature, low-pressure nitrogen inductively coupled plasma at low substrate temperatures <200 °C. The SiO_2 surface was covered with gold nanoparticles with an average diameter of 5.4 nm and irradiated with light and nitrogen radicals produced using a remote plasma. The combination of light, gold nanoparticles, and radicals including low-energy ions resulted in a conversion of the Si-O bond to Si-N, forming a nitrogen-rich SiON film. The SiON thin film (equivalent oxide thickness of 3 nm) formed at a low temperature and had a small leakage current (3 × 10~(-5) A cm~(-2)) that was comparable to a thermal oxide. It could be inferred that hot electrons supplied by surface plasmon resonance, which is unique to the gold nanoparticles, or photo-emission by ultraviolet rays promoted the reaction between the nitrogen radicals and the substrate surface.