SEMICONDUCTOR DEVICE MANUFACTURE

摘要

1522291 Semiconductor devices PHILIPS' GLOEILAMPENFABRIEKEN NV 22 April 1977 [27 April 1976] 16818/77 Heading H1K The high conductivity region of an emitter zone of L-H structure in a bipolar transistor or controlled rectifier is produced by providing a layer of initially undoped polycrystalline silicon on the lightly doped region and then introducing impurities through the layer to form the L-H structure. As described a symmetrical device is produced on an NN+ layered substrate 32 (Fig. 7) by forming a diffused or ionimplanted P type base region 4 in the N layer, epitaxially depositing the low conductivity region 8, optionally forming a 10-100 Š thick layer of silicon dioxide or nitride in an aperture in masking material, and then the undoped polysilicon 12 which is etch formed and coated with nitride prior to ion implantation, or diffusion from the oxychloride or phosphorus to produce the L-H junction which is preferably less than a minority carrier diffusion length from the emitter junction. Electrodes are then provided conventionally. In a variant the NN + collector structure forms an isolated region in a wafer which also includes a diode.