| 摘要 |
1,236,652. Photothyristors. SIEMENS A.G. 1 Aug., 1968 [5 Aug., 1967], No. 36862/68. Heading H1K. In a PNPN thyristor one of the outer zones is smaller than the adjacent inner zone to leave an area of the latter exposed. A transparent region 1-5 Á thick of the same conductivity type as the outer zone is disposed on this area. The P zones 2, 3 of a typical device, Fig. 1, are formed by diffusion or pyrolytic deposition on N-type silicon base 1 and the resulting body attached by aluminium foil 4 to molybdenum plate 6. The transparent region 8 is pyrolytically deposited or formed by alloying in a goldantimony foil and then etching in hydrogen fluoride vapour. Crescent-shaped electrode 9 and associated region 10 which partially enclose region 8 are formed by alloying in a similar foil. In an alternative construction electrode 9 is an annulus surrounding region 8. In a further embodiment in which regions 8 and 10 abut, they are formed by alloying a first foil to the site of the combined regions and after etching to leave a transparent N region alloying a second foil to only part of the film to form electrode 9. |
