Methods for selective etching of a multi-layer substrate
US8613863B2 · kind B2 · utility
13Cited by
6References
7Claims
0Family size
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Key dates
| Filing date | Nov 29, 2011 |
| Grant date | Dec 24, 2013 |
| Priority date | — |
| Expiry date | May 2, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B63/80
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method is disclosed for the selective etching of a multi-layer metal oxide stack comprising a platinum or tungsten layer on a TiN layer on an HfO2 or ZrO2 layer on a silicon substrate. In some embodiments, the method comprises a physical sputter process to selectively etch the platinum layer, followed by a first wet etch using a mixture of NH4OH and H2O2 to selectively etch the TiN layer, and a second wet etch using a dilute mixture of HF and HCl to selectively etch the HfO2 or ZrO2 layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.