Thick opaque ceramic coatings
US5776235A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 1996 |
| Grant date | Jul 7, 1998 |
| Priority date | — |
| Expiry date | Oct 4, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Thick opaque ceramic coatings are used to protect delicate microelectronic devices against excited energy sources, radiation, light, abrasion, and wet etching techniques. The thick opaque ceramic coating are prepared from a mixture containing phosphoric anhydride, i.e., phosphorous pentoxide (P.sub.2 O.sub.5), and a pre-ceramic silicon-containing material. It is preferred to also include tungsten carbide (WC) and tungsten metal (W) in the coating mixture. The coating is pyrolyzed to form a ceramic SiO.sub.2 containing coating. A second coating of plasma enhanced chemical vapor deposited (PECVD) silicon carbide (SiC), diamond, or silicon nitride (Si.sub.3 N.sub.4), can be applied over the thick opaque ceramic coating to provide hermeticity. These coatings are useful on patterned wafers, electronic devices, and electronic substrates. The thick opaque ceramic coating is unique because it is resistant to etching using wet chemicals, i.e., acids such as H.sub.3 PO.sub.4 and H.sub.2 SO.sub.4, or bases.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.