| 摘要 |
PURPOSE:To minimize the base resistance rbb of a transistor, by expanding an emitter area to the side of a base electrode window asymmetrically with respect to the electrode window. CONSTITUTION:Relation between a distance l2 from the right end of an emitter electrode window 3 to the edge on the side of abase electrode and a deviation l6 between the window and an Al wiring is made to be l2>l6. An emitter region is moved to the side of a base window independently with respect to the size and shape required for the Al wiring. Thus l5 is made to shrink and rbb is reduced. The emitter resistance re on the base electrode side is increased on the side of the base electrode by the amount corresponding to the shrinking amount DELTAl5. However, since the surface resistance of the base region is several times larger than the shrinkage, the emitter resistance can be ignored. Therefore, the effect on thermal noises can be ignored. By shrinking the width l1 of the emitter electrode window, the area of the transistor can be reduced without changing the area of the emitter region and the chip area is also decreased. Thus the bipolar transistor having the small value of rbb is obtained, and noises and high frequency characteristics can be improved.
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