Planarization method
US11569791B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 2020 |
| Grant date | Jan 31, 2023 |
| Priority date | — |
| Expiry date | Sep 4, 2041 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49005
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The invention provides a planarization method, which can make the local flatness of the product to be processed more uniform. The product has a cavity filled with oxide and includes a first electrode layer, a piezoelectric layer and a second electrode layer superposed on the cavity. The first electrode layer covers the cavity and includes a first inclined face around the first electrode layer, and the piezoelectric layer covers the first electrode layer and is arranged on the first electrode layer. The planarization method includes: depositing a passivation layer on the second electrode layer and etching the passivation layer completely until the thickness of the passivation layer is reduced to the required thickness.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.