Enhanced photodetector
US7078741B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 2003 |
| Grant date | Jul 18, 2006 |
| Priority date | — |
| Expiry date | Feb 3, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E10/548
Abstract
The present invention includes a photodiode having a first p-type semiconductor layer and an n-type semiconductor layer coupled by a second p-type semiconductor layer. The second p-type semiconductor layer has graded doping along the path of the carriers. In particular, the doping is concentration graded from a high value near the anode to a lower p concentration towards the cathode. By grading the doping in this way, an increase in absorption is achieved, improving the responsivity of the device. Although this doping increases the capacitance relative to an intrinsic semiconductor of the same thickness, the pseudo electric field that is created by the graded doping gives the electrons a very high velocity which more than compensates for this increased capacitance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.