Self-aligned methods of fabricating silicon carbide power devices by implantation and lateral diffusion
US6107142A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 8, 1998 |
| Grant date | Aug 22, 2000 |
| Priority date | — |
| Expiry date | Jun 8, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/931
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Silicon carbide power devices are fabricated by implanting p-type dopants into a silicon carbide substrate through an opening in a mask, to form a deep p-type implant. N-type dopants are implanted into the silicon carbide substrates through the same opening in the mask, to form a shallow n-type implant relative to the p-type implant. Annealing is then performed at temperature and time that is sufficient to laterally diffuse the deep p-type implant to the surface of the silicon carbide substrate surrounding the shallow n-type implant, without vertically diffusing the p-type implant to the surface of the silicon carbide substrate through the shallow n-type implant. Accordingly, self-aligned shallow and deep implants may be performed by ion implantation, and a well-controlled channel may be formed by the annealing that promotes significant diffusion of the p-type dopant having high diffusivity, while the n-type dopant having low diffusivity remains relatively fixed. Thereby, a p-base may be formed around an n-type source. Lateral and vertical power MOSFETs may be fabricated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.