Process for forming re-entrant geometry for gate electrode of integrated circuit structure
US6060375A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 1996 |
| Grant date | May 9, 2000 |
| Priority date | — |
| Expiry date | Jul 31, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/518
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A crystalline semiconductor gate electrode having a re-entrant geometry and a process for making same are disclosed. The novel gate electrode may be formed from a polysilicon layer on a substrate by first implanting a masked polysilicon layer with a neutral species, i.e., a species which will not introduce a dopant into the polysilicon, such as a Group IV element, e.g., silicon, or a Group VIII element, e.g., argon. The neutral species is implanted into the masked polysilicon layer at an angle to provide a tapered implanted region which undercuts one side of the length (long dimension) of the mask. The substrate may then be rotated 180.degree. and then again implanted to provide a tapered implanted region which undercuts the opposite side of the length of the mask. When gate electrodes with such re-entrant geometry are to be formed on a substrate with their long axes at right angles to one another, i.e., some lying along an X axis in the plane of the masked polysilicon layer on the substrate and others lying along a Y axis in the plane of the masked polysilicon layer on the substrate, the substrate may be rotated 90.degree., rather than 180.degree., between each implantation, and f…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.