| 摘要 |
PROBLEM TO BE SOLVED: To solve such a problem that an emitter area has to be enlarged for higher output and lower saturation voltage in a conventional structure so that an increase in cost due to larger size of a chip occurs. SOLUTION: A substrate is etched in a vertical direction to form a trench, and an base area is formed along the inner wall of the trench and an emitter area is formed on the surface of the base area on the inner wall of the trench. A polysilicon as an emitter diffusion source is buried in the trench and it is used as a part of an emitter electrode, capable of increasing the emitter area in the vertical direction as well as realizing lower saturation voltage and higher output without making a chip larger in size. COPYRIGHT: (C)2004,JPO&NCIPI
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