MATCHING METHOD OF HIGH-VOLTAGE ELEMENT AND LOW- VOLTAGE ELEMENT UTILIZING TRENCH ISOLATION STRUCTURE IN MANUFACTURE OF TRANSISTOR ELEMENT

摘要

PROBLEM TO BE SOLVED: To increase a current and voltage drive capabilities and to cope with the demand of the matching of high-voltage and low-voltage elements by covering a channel region and the upper section of a partial dielectric region in a gate region formed by forming and etching a gate layer and forming source-drain regions, using the gate region and the dielectric region as masks.;SOLUTION: Drift regions 15 are formed to the sidewalls and surfaces of the lower sections of trench regions by ion implantation, using the nitride film of a semiconductor substrate 11 as a main body, and oxide films are formed on the sidewalls and surface of the bottom sections of the trench regions. The nitride film and a sacrificial oxide film are removed, the oxide film is thermoformed to the surface layer of the semiconductor substrate 11, two well regions are defined, N-type ion implantation and a standard annealing process are advanced and two N-type well regions 18 are formed. The oxide film is removed, and one gate oxide film 19 and N-type-doped polysilicon 20 are formed on the upper layer of the semiconductor substrate 11. Lastly, N+-doped polysilicon and N+ source 21 and drain 22 are formed by thermal diffusion or by ion implantation.;COPYRIGHT: (C)2001,JPO