JPS54148486A - Semiconductor device - Google Patents

Abstract

PURPOSE: To increase the dielectric strength only with no increment of the saturation value by diffusing the impurities featuring the opposite conducting performance to the semiconductor layer onto the surface of the semiconductor layer which is to become the collector in such amount as not to cause the inversion in order to lower the impurity density on the surface of the semiconductor layer.

CONSTITUTION: N^--type layer 2 is grown on N⁺-type semiconductor substrate 1, and P-type base region 3 is formed by diffusion on layer 2 with N⁺-type emitter region 4 provided within region 3. Then N⁺-type channel stopper region 5 is formed by diffusion within layer 2 across region 3 and also holding region 3 between, and Al electrode 7 is attached to region 3 and 4 each. After this, the P-tupe impurities are diffused on exposed surface A of layer 2 including region 5 and in such amount as not cause the inversion into P-type with N^---type layer 8 provided, and then the entire surface is covered with SiO₂ film 6. As a result, the depletion layer caused when the backward bias is applied between the collector and the base extends completely up to stopper 5 to increase BVCEO. And Vcmsat is never increased since it is determined by region B existing between substrate 1 and region 3.

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