Patent ID: 7838378

Claim:
A method for manufacturing a semiconductor device, comprising: forming a collector region of a second conductivity type in a semiconductor substrate of a first conductivity type through implanting impurity ions of the second conductivity type into the semiconductor substrate; forming a base region of the first conductivity type in the collector region through implanting impurity ions of the first conductivity type into the collector region; forming an emitter region of the second conductivity type in the base region through implanting impurity ions of the second conductivity type into the base region; forming an emitter in the emitter region through implanting high concentration impurity ions of the second conductive type into the emitter region; forming a collector in the collector region through implanting high concentration impurity ions of the second conductive type into the collector region; and forming a base in the semiconductor substrate through implanting high concentration impurity ions of the first conductive type into the semiconductor substrate, wherein forming the emitter region of the second conductivity type and forming the base region of the first conductivity type comprise performing a rapid thermal processing, wherein forming the emitter region and forming the base region are performed at substantially the same time by the rapid thermal processing, wherein the base region comprises a P-type base region and the emitter region comprises an N-type emitter region, and wherein P-type impurity ions in the P-type base region have a higher diffusion coefficient than N-type impurity ions in the N-type emitter region, and a width of the P-type base region is self-aligned by the difference of the diffusion coefficient between the P-type impurity ions in the P-type base region and the N-type impurity ions in the N-type emitter region.