Method for forming deep trench structure
US10163647B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 26, 2017 |
| Grant date | Dec 25, 2018 |
| Priority date | — |
| Expiry date | Jan 26, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F39/811
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for forming a deep trench structure is provided. The method includes forming a first recess in a top portion of a substrate and forming a first protective layer on sidewalls of the first recess. The method includes etching a middle portion of the substrate by using the first protective layer as a mask to form a second recess and forming a second protective layer on sidewalls of the second recess. The method also includes etching a bottom portion of the substrate by using the second protective layer as a mask to form a third recess; and removing the first protective layer and the second protective layer to form a deep trench structure. The deep trench structure is constructed by the first recess, the second recess and the third recess, and the deep trench structure has a stair shape.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.