Process for removing titanium nitride layer in an integrated circuit
US5846880A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 16, 1996 |
| Grant date | Dec 8, 1998 |
| Priority date | — |
| Expiry date | May 16, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76802
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A process has been developed for removing an anti-reflective coating of titanium nitride from the surface of an aluminum layer that has been covered by a dielectric layer. Previously, this was achieved by coating said titanium nitride layer (together with the aluminum layer) with the dielectric layer and then using a single etching process to form both via holes through the dielectric and to remove the titanium nitride. When this process is used, etching proceeds reasonably quickly through the dielectric layer but becomes extremely slow once the titanium nitride is reached. In the process of the present invention, the titanium nitride layer is rapidly removed (prior to application of the dielectric layer) using a more powerful etchant. The titanium nitride/titanium layer that underlies the aluminum layer is protected during this rapid etching phase by means of a layer of a spin-on glass.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.