USE OF POCL3 FOR DIFFUSION OF PHOSPHORUS INTO SILICON

The diffusion of phosphorus into silicon using phosphorus oxychloride as the source of phosphorus has been studied. A partial doping diffusion technique has been developed to simplify the maintenance work involved during the normal diffusion runs. When accurately controlled vapors of POCl//3 diluted with oxygen and argon are fed into the diffusion system, a good control over surface concentration is achieved. By controlling the deposition time and diffusion temperature, the surface concentration of phosphorus over p-type silicon can be controlled within the range 10//1//7 to 10//2//0 atoms/cc.