Interconnect passivation and metallization process optimized to maximize reflectance
US6190936A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 18, 1999 |
| Grant date | Feb 20, 2001 |
| Priority date | — |
| Expiry date | May 18, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2201/123
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A metal surface having optimized reflectance is created utilizing the following process steps alone or in combination: 1) performing alloy/sintering of the metal-silicon interface prior to a chemical mechanical polish of the intermetal dielectric before the reflective metal electrode is formed; 2) chemical-mechanical polishing the intermetal dielectric layer again after vias are formed; 3) forming a metal adhesion layer composed of collimated titanium over the underlying dielectric; 4) depositing metal upon the adhesion layer at as low a temperature as feasible to maintain small grain size; 5) depositing at least the first layer of the reflectance enhancing coating on top of the freshly deposited metal prior to etching the metal; and 6) depositing the initial layer of the reflective enhancing coating at a temperature as close as possible to the temperature of formation of the metal electrode layer in order to suppress hillock formation in the metal. Deposition of the REC serves two distinct purposes. First, the REC coats the freshly deposited metal layer immediately following deposition, preserving the metal in its highly reflective state. Second, the REC generates constructive int…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.