Photodiode passivation technique
US7030032B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 2003 |
| Grant date | Apr 18, 2006 |
| Priority date | — |
| Expiry date | Mar 1, 2024 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E10/544
Abstract
A method for passivating a photodiode so as to reduce dark current, Isdark, due to the exposed semiconductor material on the sidewall of the device. The method includes etching away sidewall surface damage using a succinic acid-hydrogen peroxide based sidewall etch. This is followed by a subsequent hydrochloric acid (HCl)-based surface treatment which completes the surface treatment and reduces the dark current Isdark. Finally, a polymer coating of benzocyclobutene (BCB) is applied after the surface treatment to stabilize the surface and prevent oxidation and contamination which would otherwise raise the dark current were the diodes left with no coating. The BCB is then etched away from the contact pad areas to allow wirebonding and other forms of electrical contact to the diodes. Such method effectively stabilizes the etched surfaces of photodiodes resulting in significantly reduced and stable dark current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.