发明授权
- 专利标题: Double photoresist layer self-aligned heterojuction bipolar transistor
- 专利标题(中): 双光阻层自对准异质双极晶体管
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申请号: US720388申请日: 1996-09-30
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公开(公告)号: US5892248A公开(公告)日: 1999-04-06
- 发明人: Aaron K. Oki , Donald K. Umemoto , Liem T. Tran , Dwight C. Streit
- 申请人: Aaron K. Oki , Donald K. Umemoto , Liem T. Tran , Dwight C. Streit
- 申请人地址: CA Redondo Beach
- 专利权人: TRW Inc.
- 当前专利权人: TRW Inc.
- 当前专利权人地址: CA Redondo Beach
- 主分类号: H01L29/73
- IPC分类号: H01L29/73 ; H01L21/331 ; H01L29/205 ; H01L29/737 ; H01L31/0328 ; H01L27/082 ; H01L31/0336
摘要:
A heterojunction bipolar transistor and a method for fabricating an HBT with self-aligned base metal contacts using a double photoresist, which requires fewer process steps than known methods, while minimizing damage to the active emitter contact region. In particular, a photoresist is used to form the emitter mesa. The emitter mesa photoresist is left on and a double polymethylmethacrylate (PMMA) and photoresist layer is then applied. The triple photoresist combination is patterned to create a non-critical lateral alignment for the base metal contacts to the emitter mesa, which permits selective base ohmic metal deposition and lift-off. By utilizing the double photoresist as opposed to a metal or dielectric for masking, an additional photolithography step and etching step is eliminated. By eliminating the need for an additional etching step, active regions of the semiconductors are prevented from being exposed to the etching step and possibly damaged.
公开/授权文献
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