Method for reducing stray conductive material near vertical surfaces in semiconductor manufacturing processes
US5888894A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 7, 1997 |
| Grant date | Mar 30, 1999 |
| Priority date | — |
| Expiry date | Nov 7, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76895
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for reducing stray conductive material near vertical surfaces in semiconductor manufacturing processes comprising the following steps. Deposit the gate oxide, polysilicon and cap oxide layers. Apply a Poly1A mask. The Poly1A mask pattern comprises the Poly1 areas that are part of the final circuit layout as well as additional Poly1 areas that are included to provide planar surfaces to prevent stringer formation. Etch the cap, polysilicon and gate oxide layers to partially form the transistor gate structures. Form oxide spacers on the sides of the transistor gate structures. Apply a source/drain mask. Deposit source/drain dopants to form diffusions. Deposit an interlayer dielectric. Mask and pattern contacts to the diffusions and the Poly1 layer. Deposit blanket TiN/Ti layer(s). Pattern the TiN/Ti layer(s) using a TiN/Ti mask and a dry anisotropic etch. Patterning the TiN/Ti layer(s) may create TiN/Ti stringers along vertical surfaces of the interconnect layer. However, by defining the Poly1A mask pattern to leave Poly1 in pre-defined potential stringer problem areas, these surfaces remain planar and thus free of stringers. Next, apply a Poly1B mask. The Polyl1B mask is def…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.