LIGHT ACTIVATED SEMICONDUCTOR DEVICE

摘要

1283484 Light activated PNPN switch WESTINGHOUSE ELECTRIC CORP 12 June 1970 [20 June 1969] 28563/70 Heading H1K Instantaneous turn-on of a light controlled PNPN switch is achieved by providing, at the face of the semi-conductor body opposite to that on which light is incident, means for reflecting the light back into areas of the body not illuminated in the first transit. In the device illustrated in Fig. 2 the reflective means is a concentric series of grooves 50 inclined at an angle of >16-5 degrees to the lower surface of the silicon body. This ensures total internal reflection when using radiation from a neodymium doped laser 42. A single groove may alternatively be used in which case its intersections with the PN junctions in the body must be passivated. Preferably to improve reflection aluminium is evaporated over the surfaces of the body abutting the copper electrodes and sintered at 500‹ C. for 20 minutes.