Abstract: [PROBLEMS] To provide a semiconductor element manufacturing method by which a semiconductor element having high accuracy and high function can be manufactured by controlling diffusion depth and diffusion concentration in a pn junction region with high accuracy. [MEANS FOR SOLVING PROBLEMS] A diffusion control layer (2) composed of a thin film of a substance having a smaller diffusion coefficient than that of a diffusion source (3) is formed between a surface of a substrate (1) and the diffusion source (3), and an element of the diffusion source (3) is permitted to thermally diffuse through the diffusion control layer (2). Thus, the diffusion depth and the diffusion concentration in the semiconductor region, which is formed on the surface portion of the substrate and has a conductivity type different from that of the substrate, can be highly accurately controlled, and the semiconductor element having high accuracy and high function can be manufactured.

Abstract: [PROBLEMS] To provide a semiconductor element manufacturing method by which a semiconductor element having high accuracy and high function can be manufactured by controlling diffusion depth and diffusion concentration in a pn junction region with high accuracy. [MEANS FOR SOLVING PROBLEMS] A diffusion control layer (2) composed of a thin film of a substance having a smaller diffusion coefficient than that of a diffusion source (3) is formed between a surface of a substrate (1) and the diffusion source (3), and an element of the diffusion source (3) is permitted to thermally diffuse through the diffusion control layer (2). Thus, the diffusion depth and the diffusion concentration in the semiconductor region, which is formed on the surface portion of the substrate and has a conductivity type different from that of the substrate, can be highly accurately controlled, and the semiconductor element having high accuracy and high function can be manufactured.