SEMICONDUCTOR DEVICE MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To ensure the withstand pressure of a semiconductor element that contains a parallel pn structure fabricated by a trench-embedded method as a drift portion. SOLUTION: An n-type semiconductor is epitaxially grown on an n-type low resistance substrate 1 and a trench is formed on the n-type semiconductor. A p-type semiconductor is epitaxially grown and a trench is buried with the p-type semiconductor. The surfaces of an n-type area 5 made of n-type semiconductors and a p-type area 6 made of p-type semiconductors are both ground to be flat, and then boron is selectively injected into the p-type area 6 that becomes an inactive area. In a non-oxidative atmosphere, thermal treatment takes place to activate the injected boron. A field oxidized film is formed by thermal oxidation. An element structure at the MOSFET surface side, a source electrode and a channel stopper electrode are formed and a drain electrode is provided at the rear of the substrate 1. COPYRIGHT: (C)2006,JPO&NCIPI