Lithographic process
US7910292B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 1, 2004 |
| Grant date | Mar 22, 2011 |
| Priority date | — |
| Expiry date | Dec 10, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/20
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention provides a lithographic process for producing high aspect ratio parts from an epoxy-type negative photoresist comprising the steps of: (i) irradiating a prebaked masked epoxy-type negative photoresist on a substrate with light at a total energy density of from 18,000 to 35,000 mJ/cm2, (ii) post-baking the exposed photoresist at elevated temperature, and (iii) developing the exposed photoresist in a solvent, wherein no more than 15% of the energy density is contributed by light having a wavelength of 400 nm or less. The invention also discloses a reciprocating microengine (10) comprising a cylinder (14), piston (12) and crankshaft made by the process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.