Diffusion and doping of Si into GaAs from undoped SiO<i>x</i>/SiN film

Abstract

The diffusion and n-type doping of Si into GaAs from a novel diffusion source consisting of an undoped SiOx/SiN double-layered film were achieved by rapid thermal annealing at 860–940 °C. The film properties of the double-layered films employed as Si diffusion sources are experimentally presented. The characteristics of the Si diffused layers were investigated by secondary ion mass spectrometry, capacitance-voltage measurement, and the Hall method. The carrier profiles exceeded 2×1018 cm−3 and featured an abrupt diffusion front, while a maximum electron concentration of 6×1018 cm−3 was obtained at 940 °C. The diffused Si profiles were consistent with the SiGa+−VGa− pair diffusion model.