| 摘要 |
PURPOSE:To reduce deterioration of characteristic such as junction leak by a method wherein the level difference of Si used for mask-matching after formation of a well layer can be formed in a heat treatment process after injection of ion into the well layer. CONSTITUTION:A thermo-oxidized film 2 is formed on an N type Si semiconductor substrate 1 and further thereon a nitrified film 9 is formed. Next, by using a photoresist 3 as a mask, the film 8 located in a region where the P well layer is formed is removed. Then, by using the resist 3 and the film 9 as the mask, a boron ion is injected, through the intermediary of the film 2, into the region where the P well layer is formed. Next, after the resist 3 being removed, oxidization for intrusion of the P well layer and for formation of the level difference of Si for mask-matching applied ina subsequent process is performed simultaneously by application of heat treatment in an inactive fas containing oxygen. By forming the level difference of Si in this way without application of thermal oxidization for hours, deterioration of characteristic such as junction leak harmful for C-MOSIC can be reduced. |
