| 摘要 |
PURPOSE:To reduce output conductance and thus make it difficult to generate punch-through by a method wherein the collector region is changed into a P type low density region. CONSTITUTION:After the thermal diffusion of a P type emitter region 3 and a collector region 2 into an N type epitaxial layer 1, the ion implantation heat- treatment of N type is performed to the P type collector region 2, which is thus changed into the low density diffused P type collector region 21 by decreasing the density of approx. 1X10<18>atom/cm<3> before the treatment. The density of the P type collector region 21, if treated so as to become e.g. approx. 9.9X10<17>atom/ cm<3>, becomes approx. 1X10<16>atom/cm<3> by the compensation of a P type impurity and an N type impurity. By decreasing the density of the collector region, the expansion of a depletion layer of the base region becomes small, and then punch-through becomes difficult to generate. |
