Method for manufacturing hybrid image sensors
US7820525B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 25, 2009 |
| Grant date | Oct 26, 2010 |
| Priority date | — |
| Expiry date | Mar 25, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/351
Abstract
A method for wafer-to-wafer bonding of a sensor readout circuitry separately fabricated with a silicon substrate to a photodiode device made of non-silicon materials grown from a separate substrate. In preferred embodiments the non-silicon materials are epitaxially grown on a silicon wafer. The bonding technique of preferred embodiments of the present invention utilizes lithographically pre-fabricated metallic interconnects to connect each of a number of pixel circuits on a readout circuit wafer to each of a corresponding number of pixel photodiodes on a photodiode wafer. The metallic interconnects are extremely small (with widths of about 2 to 4 microns) compared to prior art bump bonds with the solder balls of diameter typically larger than 20 microns. The present invention also provides alignment techniques to assure proper alignment of the interconnects during the bonding step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.