Method of fabricating aLDD field-effect transistor
US4826782A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 17, 1987 |
| Grant date | May 2, 1989 |
| Priority date | — |
| Expiry date | Apr 17, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/03
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An intermediate structure in the fabrication of a metal-oxide semiconductor field-effect transistor is made from a substrate of p+ silicon having an elongate insulated gate structure on its main face. First and second areas of the main face are exposed along first and second opposite sides respectively of the gate structure. Donor impurity atoms are introduced into the substrate by way of at least the first area of the main face, to achieve a predetermined concentration of electrons in a region of the substrate that is subjacent the first area of the main face. The gate structure is opague to the impurity atoms. A sidewall of silicon dioxide is formed along the first side of the gate structure, whereby a strip of the first area of the main face is covered by the sidewall and other parts of the first area remain exposed adjacent the sidewall. Donor impurity atoms to which the gate structure and the sidewall are opaque are introduced into the substrate by way of the portion of the first area that is exposed adjacent the sidewall. A layer of polysilicon is disposite over the portion of the first area of the main face that is exposed adjacent the sidewall. This layer extends up the sid…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.