PLANAR TYPE VERTICAL BIPOLAR PHOTOTRANSISTOR

摘要

PURPOSE:To prevent the decrease in the current amplification factor of a planar vertical bipolar phototransistor by covering the edge of the bonding surface of an emitter and a base through an insulating film with an electrode, thereby absorbing a leakage electric field. CONSTITUTION:An emitter electrode extends through a surface insulating film 6 cover the edge 43' of the bonding surface of an emitter and a base. The extending margin may be at least approx. 4mum from the edge to the side of the base layer 3. The base surface 31 contacting the emitter layer 4 under the emitter electrode thus expanded in shape is shield from the external electric field. Even if an inverted layer is formed on the other surface of the base layer, it is shielded by the base surface 31, is not connected the emitter layer, and the photoconversion efficiency does not decrease accordingly.