| 摘要 |
PURPOSE:To form a high concentration and shallow diffusion layer on the surface of semiconductor substrate and suppress the generation of protruded spots by executing heat processing for a short period of time after applying liquid impurity diffusion source to the surface of semiconductor substrate. CONSTITUTION:After applying a diffusion source 3 to a semiconductor substrate 1, heat processing is executed for 3hr at 1,230 deg.C. In this case, dust adheres onto an oxide film 2 and if the melting point drops, diffusion completes within an oxide film 2 and does not reach the semiconductor substrate 1. Thereafter, the applied diffusion source is removed by washing the semiconductor substrate with the aqueous solution of fluoric acid and a shallow diffusion layer 5 can be obtained in the desired diffusion region. Thereafter, heat processing is conducted to the semiconductor substrate for 7hr at 1,230 deg.C. The desired deep diffusion layer can be formed and the diffused layer is not formed to the unnecessary oxide film 2 because there is no diffusion source. Accordingly, unnecessary diffusion region is not generated. |
