| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that surface roughness of a contact bottom is caused by overetching in a conventional manufacturing method, thus increasing characteristic dispersion of a semiconductor device. SOLUTION: A bipolar transistor is formed having a collector region 4 provided to a bottom of a trench formed in a p-type silicon substrate 1. An interlayer dielectric 23 is formed on the p-type silicon substrate 1. A part 30 of a collector contact opening is formed by etching halfway the interlayer dielectric 23 of an upper part of the trench. A remaining portion 32 of the collector contact opening is formed by etching the interlayer dielectric 23 of an upper part of the trench to attain to the bottom. Formation of the remaining portion 32 of the collector contact opening is executed simultaneously with formation of an emitter contact opening 25 and a base contact opening 27. COPYRIGHT: (C)2008,JPO&INPIT
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