Avalanche photodiode with edge breakdown suppression
US7834379B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 15, 2008 |
| Grant date | Nov 16, 2010 |
| Priority date | — |
| Expiry date | Dec 5, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E10/544
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The invention relates to an avalanche photodiode having enhanced gain uniformity enabled by a tailored diffused p-n junction profile. The tailoring is achieved by a two stage doping process incorporating a solid source diffusion in combination with conventional gas source diffusion. The solid source diffusion material is selected for its solubility to the dopant compared to the solubility of the multiplication layer to dopant. The solid source has a diameter between the first and second diffusion windows. Thus, there are three distinct diffusion regions during the second diffusion. The dopant in the multiplication layer at the edge region, the dopant from the solid source material with a relatively higher dopant concentration (limited by the solubility of the dopant in the solid source material) at the intermediate region, and the central region exposed to an infinite diffusion source from the solid source material as it is continually charged with new dopant from the external gas source. The result is that both the dopant concentration and the diffusion depth decrease gradually from the center to the edge of the device. This tailored diffusion profile enables control of the electr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.