| 摘要 |
1279376 Semi-conductor devices SIEMENS AG 19 April 1971 [19 Feb 1970] 21660/71 Heading H1K The conductivity and/or conductivity type of part of a semi-conductor body 1 is modified by diffusion from a layer 2 comprising an oxide of a dopant and covered by a layer 4 of SiO 2 which prevents impoverishment of the dopant from the layer 2 into the gas phase during the diffusion heating step. The layer 2, which may comprise the oxide of Sb, B, P or As for a Si body 1, and the layer 4 are formed by depositing a layer of a lacquer containing a compound of the dopant in solution, e.g. a photo-sensitive lacquer or nitrocellulose dissolved in a butyl acetateether mixture and containing SbCl 3 in solution; evaporating off the solvent, shaping the remaining layer 2 by etching, depositing a coating comprising a solution of a silicon compound; e.g. a solution of SiCl 4 or a further lacquer of the abovedescribed type but containing dimethyldichlorsilane instead of SbCl 3 ; and heating in a moist atmosphere to decompose the lacquer base and leave the oxide layers 2 and 4. After diffusion the semi-conductor body 1 is left with a coating of SiO 2 overlying a layer containing mixed oxides of the dopant and Si on the diffused areas. The invention is applicable to the manufacture of Si NPN or PNP transistors. |
