| 摘要 |
PURPOSE:To produce efficiently a semiconductor element with low sheet resistance at a high uniformity and reproducibility by diffusion from a thin film multiple layer comprising a thin layer containing impurity of high density. CONSTITUTION:After a first layer thin film A comprising silicon oxide film containing no diffusion impurity has been formed on a substrate of N type silicon, paint material containing boron trioxide is formed as a second layer thin film B containing diffusion impurity of high density and further ethyl silicate is formed as a third layer thin film A' containing no diffusion impurity. Consequently the semiconductor substrate on which the foregoing three thin film multiple layers are formed is inserted into the diffusion furnace. Further, the diffusion treatment is provided while continuing heating at a predetermined temperature and controlling the density of the diffusion impurity in the atmosphere within the diffusion furnace to supply the impurity equivalent substantially to the impurity amount diffused from the thin film B containing the diffusion impurity at a high density into the substrate to the thin film B. According to such a process, the diffusion layer with low sheet resistance can be obtained. |
