| 摘要 |
1467263 Semi-conductor devices HONEYWELL Inc 5 Feb 1974 [5 Feb 1973] 5321/74 Heading H1K In a method of making a semi-conductor device, as shown a bipolar transistor, a diffused P+ region 11, Fig. 3, is formed below a major surface of an isolated portion of an N- type epitaxial silicon layer 10, an apertured insulating layer 12 is formed thereover, and the surface exposed by the aperture is covered by a layer 14 of N-doped polycrystalline silicon. The structure is then heated to effect diffusion of acceptor impurities from region 11 further into layer 10, and of donor impurities from layer 14 into the central part of region 11 to form a N ++ emitter region 15, Fig. 6. The donor impurity is preferably arsenic, which locally reduces the diffusion rate of the preferred acceptor impurity, boron, to form a narrow necked base region 11<SP>11</SP>. Layer 14 is then etched to leave an emitter contact 14<SP>1</SP>; a layer 17 of phosphorus-doped SiO 2 is deposited overall, melted, resolidified, and photo-etched to expose contact 14<SP>1</SP>, a base contact region 11<SP>1</SP>, and an N-type sinker to a buried collector layer (not shown); and metallization (e.g. Al) follows to form emitter, base and collector electrodes 18, 19. An additional metal contact 21 is provided to a doped polysilicon layer 20 which acts as a cross-under path or resistor. A pinch resistor may be made by the inventive method. - |
