Method of undercutting micro-mechanical device with super-critical carbon dioxide
US6737225B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 28, 2001 |
| Grant date | May 18, 2004 |
| Priority date | — |
| Expiry date | Apr 9, 2022 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB81C2201/117
- WIPO fieldMicro-structural and nano-technology
- WIPO sectorChemistry
Abstract
A method for removing sacrificial layers during the process of fabricating micro-mechanical devices with a solution of super-critical carbon dioxide. A mixture of super-critical carbon dioxide with other solvents, co-solvents and surfactants is used during the process to remove sacrificial layers. The disclosed method has many advantages over the prior art, including a reduction of capillary forces that can damage the free-standing micro-mechanical superstructures, an absence of plasma induced damage caused by ashing operations, and a reduction in the use of environmentally sensitive chemicals. Another advantage of the disclosed process is that the swelling of the photoresist layers is minimized. The disclosed method may be used to remove sacrificial layers that were deposited during the process of fabricating micro-mechanical devices. The method is also effective to remove a protective recoat layer that is deposited over a micro-mechanical device after it has been fabricated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.