| 摘要 |
PURPOSE:To implement a high speed and miniaturization, by providing a plurality of parallel grooves at parts, where channel stoppers are formed, and providing the channel stopper regions by performing heat treatment in a P or B atmosphere. CONSTITUTION:SiO2 2 and Si3N4 3 are deposited on a P-type Si substrate 1. A plurality of grooves, whose widths and intervals are 1mum or less, are etched in channel stopper regions, by etching the Si3N4 3. The grooves 4 are formed by anisotropic etching 7 by using the mask 3. Then, B ions are implanted, and a P<+> layer 5 is provided. The entire substrate at the groove parts undergoes thermal oxidation, and a field oxide film 6 is formed. Then, heat treatment is performed in the P atmosphere, and the surface of the SiO2 6 is made to be PSG and softened at 1,000 deg.C or more. Remaining slight gaps of the grooves are filled with the PSG. As a result, the thick field oxide film 6 corresponding to the depths of the grooves can be formed without birds' beaks. When a MOSFET is further formed, a minute device characterized by a high speed is obtained.
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