| 摘要 |
PURPOSE:To contrive the prevention of generation of crystal defects and the improvement in yield by a method wherein a relatively thin SiO2 film is formed in a periphery of an element and a base region is brought in contact with said film and an enough thick oxide layer is formed in a field part distant from the element part by self alignment. CONSTITUTION:An N<+> type collector buried layer is formed on a silicon substrate 1 and after removing an oxide film mask, an N type epitaxial layer 3 is formed followed by growing of a silicon dioxide film 4 and a silicon nitride film 5. An extremely thin Si3N4 film 5' is formed over the whole surface which is then coated with a photoresist 16 and the resist of an insulating isolation layer forming region is removed. The peripheral part contacting with the insulating isolation layer is left by covering the thin Si3N4 film with the resist. After that, a thick silicon dioxide layer 7 is formed by heating at about 1,000 deg.C in a wet O2 gas. The thin Si3N4 film changes into an SiO2 film of about 3,000Angstrom thick and in the insulating isolation layer region, a thick SiO2 insulating layer of about 1.0mum is formed. Consequently, a deterioration of the characteristics such as the element isolation characteristics does not occur and the generation of crystal detects can be prevented. |
