Preparation of semiconductor device

Abstract

Abstract PURPOSE:To provide a method of manufacturing element isolation structure of semiconductor device realizing a high integration density by forming element region and element isolation region with high accuracy to the designed dimensions with a very small bird beak. CONSTITUTION:A silicon dioxide film 23A, a silicon nitride film 23 and a silicon dioxide film 22 are removed respectively by etching with a photo resist film 24 used as the mask resistive to etching. Moreover, a silicon substrate 2 is removed by etching with the photo resist film 24 and the silicon dioxide film 23A used as the mask resistive to etching and a groove A is formed. Thereafter, the photo resist film 24 is removed. A silicon dioxide film 25 is formed on the surface of groove A by the thermal oxidation method, boron B etc. is ion implanted as the impurity having the same conductivity type as the substrate to the bottom of groove A as the channel stopper, and a thick polycrystalline silicon 26 is formed by the CVD method at the entire part of wafer for filling the groove. Then, polycrystalline silicon 26 is removed by etching up to the area near the surface of silicon nitride film 23', leaving the polycrystalline silicon 26' only to the groove A. Thereafter, the silicon dioxide film 23A' is removed by etching. The polycrystalline silicon 26' is oxidized by the thermal oxidation method with the silicon nitride film 23' used as the mask resistive to oxidaton and thereby a thick silicon dioxide film 27 is formed at the upper part of the groove A.

Inventors

• 👤 Toshiyuki Ishijima
• 👤 石嶋　俊之

Bibliographic Details