Wet etching of samarium selenium for piezoelectric processing
US10269580B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 6, 2017 |
| Grant date | Apr 23, 2019 |
| Priority date | — |
| Expiry date | Nov 6, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N30/853
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A subtractive forming method that includes providing a material stack including a samarium and selenium containing layer and an aluminum containing layer in direct contact with the samarium and selenium containing layer. The samarium component of the samarium and selenium containing layer of the exposed portion of the material stack is etched with an etch chemistry comprising citric acid and hydrogen peroxide that is selective to the aluminum containing layer. The hydrogen peroxide reacts with the aluminum containing layer to provide an oxide etch protectant surface on the aluminum containing layer, and the citric acid etches samarium selectively to the oxide etch protectant surface. Thereafter, a remaining selenium component of is removed by elevating a temperature of the selenium component.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.