- 专利标题: Metallization over tungsten plugs
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申请号: US423397申请日: 1995-04-18
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公开(公告)号: US5786272A公开(公告)日: 1998-07-28
- 发明人: Maria Santina Marangon , Andrea Marmiroli , Giorgio Desanti
- 申请人: Maria Santina Marangon , Andrea Marmiroli , Giorgio Desanti
- 申请人地址: ITX Agrate Brianza
- 专利权人: SGS-Thomson Microelectronics S.r.l.
- 当前专利权人: SGS-Thomson Microelectronics S.r.l.
- 当前专利权人地址: ITX Agrate Brianza
- 优先权: EPX92830265 19920527
- 主分类号: H01L21/28
- IPC分类号: H01L21/28 ; H01L21/768 ; H01L21/44
摘要:
A plug contact process wherein, after contact holes are etched, an adhesion layer (such as Ti/TiN) and a filler metal (such as tungsten) are deposited overall. A two-stage etch is then used: First, the filler metal is etched preferentially with respect to the adhesion layer, until an endpoint signal first indicates that said adhesion layer is exposed. No overetch is used at this stage. Thereafter a nonpreferential etch is used to clear residues of the filler metal, while also uniformly reducing the height of the adhesion layer. This prevents the tops of the plugs in the contact holes from being recessed. Aluminum (or other metal) is then deposited and patterned (using a stack etch to remove the undesired portions of the adhesion layer too) to implement the desired wiring pattern. This process thereby reduces voids, and resulting metallization defects, in a process with high-aspect-ratio contacts. In addition, the residual adhesion layer helps to reduce electromigration.
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