| 摘要 |
A MOS type semiconductor device, comprises a semiconductor layer (1) of a first conductivity type, and a plurality of MOS type rectangular cells, each having four major sides including short and long major sides and including a channel region (3) of a second conductivity type formed in a surface layer of the semiconductor layer (1), and one or more source regions (4) of the first conductivity type formed in the surface layer of the channel region (3), at least two sides of said one or more source regions (4) lying in parallel to at least two sides of the channel region; wherein said plurality of rectangular cells are formed in a central portion of a semiconductor chip and MOS type peripheral cells are formed in a peripheral portion of the semiconductor chip, the peripheral cells including a channel region (3) of the second conductivity type and a source region (4) of the first conductivity type, and at least a portion of the outermost side of the channel region of the peripheral cells lies in parallel to a respective side of the semiconductor chip. The the area of a peripheral cell (19) is greater than that of a rectangular cell; the channel regions (3) of first and second neighbouring cells, which have the short major sides facing each other in parallel, are joined along the facing short major sides thereof; and a base region (11) of the second conductivity type is formed in a portion of the surface layer of the channel region (3), the impurity concentration of the base region being higher and its diffusion depth being shallower than those of the channel region. <IMAGE> |
