Dual wafer attachment process
US6287940A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 2, 1999 |
| Grant date | Sep 11, 2001 |
| Priority date | — |
| Expiry date | Aug 2, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Producing the microstructures on separate substrates, which are bonded. One of these structures may be temperature sensitive CMOS electronics. There may be a high-temperature thermal sensor on one wafer and low-temperature CMOS electronics. In the case where the bonding material is polyimide, the polyimide on both surfaces to be bonded is soft baked. The wafers are placed in a wafer bonder and, using precision alignment, brought into contact. The application of pressure and heat forms a bond between the two coatings of polyimide. A wafer may need to be removed from a combined structure. One of the bonded structures may be placed on a sacrificial layer that can be etched away to facilitate removal of a wafer without grinding. After wafer removal, a contact from the backside of one of the structures now on polyimide to the other on the wafer may be made. Sacrificial material, for example, polyimide, may be removed from between the structures that are connected via a contact. A microstructure may be bonded with something that is not a microstructure, such as single-or multi-layer material, crystalline or amorphous.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.