Manufacture of semiconductor device

Abstract

Abstract PURPOSE:To form a channel-cut region simply to the side surface of a buried isolation region by mixing a gas containing an impurity having the same conduction type as a semiconductor substrate besides an etching gas when a groove is shaped through RIE. CONSTITUTION:A semiconductor substrate 1 is etched through RIE using trifluoromethane as an etching gas while employing a resist 4 as a mask to form a groove 6 in 0.5mum width. Boron trichloride, etc. may be used besides carbon tetrachloride as the etching gas. When an impurity gas having the same conduction type as the semiconducor substrate such as diborane gas is made to be contained at that time, boron dissociating by plasma is taken into the substrate from the surface of the groove to shape a boron uptake layer 7. The resist 4 is removed, and an SiO2 layer is formed onto the inner surface of the groove as a second insulating layer 8 while employing an Si3N4 layer 3 as a mask through termal oxidation at 1,000 deg.C. A P<+> type impurity layer 7A is formed simultaneously through the heat treatment.

Inventors

• 👤 Satoru Fukano
• 👤 深野　哲
• 👤 Koichiro Kotani
• 👤 小谷　紘一郎

Bibliographic Details