发明名称 Transistor and method of forming the transistor so as to have reduced base resistance
摘要 Disclosed is a transistor structure, having a completely silicided extrinsic base for reduced base resistance Rb. Specifically, a metal silicide layer covers the extrinsic base, including the portion of the extrinsic base that extends below the upper portion of a T-shaped emitter. One exemplary technique for ensuring that the metal silicide layer covers this portion of the extrinsic base requires tapering the upper portion of the emitter. Such tapering allows a sacrificial layer below the upper portion of the emitter to be completely removed during processing, thereby exposing the extrinsic base below and allowing the metal layer required for silicidation to be deposited thereon. This metal layer can be deposited, for example, using a high pressure sputtering technique to ensure that all exposed surfaces of the extrinsic base, even those below the upper portion of the emitter, are covered.
申请公布号 US8846481(B2) 申请公布日期 2014.09.30
申请号 US201314135664 申请日期 2013.12.20
申请人 International Business Machines Corporation 发明人 Cantell Marc W.;Doan Thai;Levy Jessica A.;Liu Qizhi;Murphy William J.;Willets Christa R.
分类号 H01L21/331;H01L29/66;H01L29/08;H01L21/8222;H01L29/737;H01L29/732 主分类号 H01L21/331
代理机构 Gibb & Riley, LLC 代理人 Gibb & Riley, LLC ;Cain, Esq. David A.
主权项 1. A method of forming a transistor, said method comprising: performing at least one etch process so as to create, from a polysilicon layer, an emitter comprising: a lower portion and an upper portion above said lower portion, said lower portion being on an intrinsic base and positioned laterally adjacent to a dielectric spacer, andsaid upper portion being wider than said lower portion, extending laterally over said dielectric spacer onto a sacrificial layer and having a tapered sidewall; selectively removing said sacrificial layer so as to expose an extrinsic base positioned laterally adjacent to said dielectric spacer opposite said lower portion of said emitter, said upper portion of said emitter extending laterally over said extrinsic base; and, forming a silicide layer on said extrinsic base such that said silicide layer is positioned laterally immediately adjacent to said dielectric spacer opposite said lower portion of said emitter and such that said upper portion of said emitter extends laterally over said silicide layer; forming a dielectric layer on said silicide layer such that said dielectric layer is positioned laterally immediately adjacent to said dielectric spacer opposite said lower portion of said emitter and further positioned vertically between and immediately adjacent to said silicide layer and said tapered sidewall of said upper portion of said emitter.
地址 Armonk NY US