Method and apparatus for the selective doping of semiconductor material by ion implantation
US6284615A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 16, 1999 |
| Grant date | Sep 4, 2001 |
| Priority date | — |
| Expiry date | Jun 16, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D10/054
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The method comprises forming an implantation screening layer of predetermined thickness on the wafer, forming, in the screening layer, a first rectilinear, elongate opening having a first width, and at least a second rectilinear, elongate opening substantially parallel to the first opening and having a second width smaller than the first width is formed on the screening layer. The wafer is then subjected to ion implantation with two ion beams directed in directions substantially perpendicular to the longitudinal axes of the openings and inclined to the surface of the wafer at predetermined angles so as to strike the openings from two opposite sides. The thickness of the screening layer, the widths of the openings, and the angles of inclination of the ion beams being selected in a manner such that the beams strike the base of the first opening for substantially uniform doping of the underlying area of the wafer, but do not strike the base of the second opening. The novel method and apparatus enables selective doping by ion implantation to be performed without the use of a mask which is otherwise necessary for screening the second opening.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.