Method of forming a high electromigration resistant metallization system
US5776831A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 27, 1995 |
| Grant date | Jul 7, 1998 |
| Priority date | — |
| Expiry date | Dec 27, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/28512
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of forming a metallization system in which ohmic contact is made to a silicon surface is described. A first layer of titanium is formed over the silicon surface. This first titanium layer is subsequently annealed in a nitrogen atmosphere to convert a first portion of the layer to a layer of titanium silicide, and a second portion to a first layer of titanium nitride. The titanium silicide layer provides for the formation of an ohmic contact between the metallization system and the silicon surface. The first titanium nitride layer provides for a degree of spike resistance between the silicon surface and the metallization system. A second layer of titanium nitride is formed over the first titanium nitride layer. This second titanium nitride layer provides further spike resistance between the silicon surface and the metallization system. A second titanium layer is then formed over the second titanium nitride layer, and acts to wet the surface of the second layer of titanium nitride, and aides in the flow of subsequently deposited layers across the second titanium nitride layer. An aluminum layer is formed over the second titanium layer, for providing a low ohmic resistance pa…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.