Maintaining photoresist planarity at hole edges
US7005236B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 23, 2003 |
| Grant date | Feb 28, 2006 |
| Priority date | — |
| Expiry date | Dec 11, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/0035
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Maintaining photoresist thickness and uniformity over a substrate that includes various cavities presents problems, such as preventing distortion of features in the resist image close to cavity edges. These problems have been overcome by laying down the photoresist as two separate layers. The first layer is used to eliminate or reduce problems associated with the presence of the cavities. The second layer is processed in the normal way and does not introduce distortions close to a cavity's edge. A first embodiment introduces some liquid into the cavity before laying down the first layer while the second embodiment etches away part of the first layer before applying the second one. Application of the process to the formation of a cantilever that overhangs a cavity is also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.