Controlled bond formation between chemical vapor deposition Si and ultrathin SiO2 layers

This article reports that chemically active sites on SiO2 surfaces can be either passivated or introduced intentionally by treating them in a proper chlorosilane gas, SiHnCl4−n (n=0,1,2). Our experiments of Si chemical vapor deposition on SiO2-covered Si have shown that Si deposition is suppressed on SiCl4- and SiHCl3-treated samples, while an SiH2Cl2 treatment drastically enhances Si nucleation. Thus, the chlorosilane treatment is a unique way for us to control the interface bonds between the SiO2 surface and the Si deposits on it. We also demonstrate resistless selective-area deposition using a SiHCl3-treated ultrathin SiO2 mask layer. Patterns are defined on the mask surface by direct electron-beam irradiation which induces Cl desorption thereby forming chemically reactive surface defects.