| 摘要 |
PURPOSE:To obtain the titled device of high photo receiving sensitivity by a method wherein a recess is formed at part of the surface of a semiconductor substrate, as well as the base at the region including the recess, and the emitter region at the bottom of the recess. CONSTITUTION:The recess 23 is formed in an epitaxial layer 20 on the Si substrate 21. Thereafter, the base 19 and the emitter 17 are formed by impurity diffusion in this order. The epitaxial layer 20 of the collector has a specific resistance of 20OMEGAcm and a thickness of 60mum. Since the thickness of the epitaxial layer of the collector is made larger in the part other than the one immediately under the emitter, the generated amount of carriers corresponding to a given photo input increases, and the photo current becomes larger by a magnitude of 2.4 times when a light of 9,400Angstrom wavelength is used. |
