Ultrashallow, high doping of boron using molecular layer doping

A new doping method named molecular layer doping (MLD) is proposed. MLD is based on surface chemical adsorption of dissolvements from induced dopant gas molecules. Ultrashallow boron-doped layers are successfully achieved by MLD using B2 H6 gas. The p+ n junction formed by MLD exhibits excellent characteristics, with a reverse bias leakage current of less than 2.5×10−16 A/μm2 at 5 V. MLD is attractive in that it offers high-density, shallow-junction, damage-free, selective doping in a short time.