Method of forming multiple-layer microlenses and use thereof
US5871888A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 11, 1996 |
| Grant date | Feb 16, 1999 |
| Priority date | — |
| Expiry date | Jul 11, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B3/0056
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method of forming refractive microlenses which includes the steps of depositing or growing a first transparent layer on a substrate; depositing or growing a second transparent layer on the first transparent layer; forming a columnar structure in the second transparent layer; forming a pillar in the first transparent layer using the columnar structure as a mask, whereby the pillar is self-aligned under the columnar structure and the pillar has a cross-sectional area smaller than or equal to the cross-sectional area of the columnar structure; thereafter reflowing the second transparent layer of the columnar structure while the pillar remains essentially unaltered, whereby a structure is formed on top of the pillar, the structure having a ground plane with an area smaller than or equal to the original cross-sectional area of the columnar structure; and solidifying said structure. Due to the surface tension, the pillar underneath the microlens confines the reflow of the microlens to an area smaller or equal to the original cross-sectional area of the lens-forming columnar structure. A major effect of this is that the microlens has a strong curvature, and hence, a large numerical aper…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.