Radiation hardening method for shallow trench isolation in CMOS
US6890832B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 2002 |
| Grant date | May 10, 2005 |
| Priority date | — |
| Expiry date | Oct 11, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/911
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A radiation-hardened STI process includes implanting a partially formed wafer with a fairly large dose (1013 to 1017 ions/cm2) of a large atom group III element, such as B, Al, Ga or In at an energy between about 30 and 500 keV. The implant is followed by an implant of a large group V element, such as P, As, Sb, or Bi using similar doses and energies to the group III element. The group V element compensates the group III element. The combination of the two large atoms decreases the diffusivity of small atoms, such as B, in the implanted areas. Furthermore, the combination of the group III and group V elements in roughly equal proportions creates recombination sites and electron traps in the field oxide, resulting in a radiation hardened semiconductor device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.