| 摘要 |
PURPOSE:To enable forming a diffusion layer in required dimensions precisely by heat treatment coating silicate glass film which contains no impurity on all the surface after patterning a film of silicate glass which contains impurity coated on a semiconductor substrate. CONSTITUTION:A silicate glass film which contains impurity is coated on the surface of a P type silicon substrate 1 by spin-on-coating and a silicate glass film 3 which contains impurity of a required pattern is obtained. Arsenic is used as impurity. Then, a silicate glass film 5 which contains no impurity is formed o all the surface of the substrate 1 and the patterned silicate glass film 3 by spin- on-coating. After two layers of the silicate glass films 3, 5 are formed, all of these are heat-treated and the impurity is homogeneously diffused in the silicon substrate 1. Since the silicate glass film 3 which contains impurity is covered by the silicate glass 5 which contains no impurity, the atoms of the impurity are evaporated by heat treatment and the autodoping of the other parts is prevented. |
