Ti/Tinx underlayer which enables a highly <111> oriented aluminum interconnect
US6420260B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 2000 |
| Grant date | Jul 16, 2002 |
| Priority date | — |
| Expiry date | Oct 24, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The present disclosure pertains to particular Ti/TiN/TiNx barrier/wetting layer structures which enable the warm aluminum filling of high aspect vias while providing an aluminum fill exhibiting a high degree of aluminum <111> crystal orientation. It has been discovered that an improved Ti/TiN/TiNx barrier layer deposited using IMP techniques can be obtained by increasing the thickness of the first layer of Ti to range from greater than about 100 å to about 500 å (the feature geometry controls the upper thickness limit); by decreasing the thickness of the TiN second layer to range from greater than about 100 å to less than about 800 å (preferably less than about 600 å); and, by controlling the application of the TiNx third layer to provide a Ti content ranging from about 50 atomic percent titanium (stoichiometric) to about 100 atomic percent titanium. Preferably the TiNx third layer is formed at the end of the deposition of the TiN second layer and exhibits a Ti content gradient which begins at a stoichiometric, 50 atomic percent, Ti content and ends at a Ti content of about 100 atomic percent. The thickness of the TiNx third layer preferably ranges fro…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.