Method for forming silicon nitride film selectively on sidewalls or flat surfaces of trenches
US9754779B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 19, 2016 |
| Grant date | Sep 5, 2017 |
| Priority date | — |
| Expiry date | Feb 19, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31111
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for fabricating a layer structure in a trench includes: simultaneously forming a dielectric film containing a Si—N bond on an upper surface, and a bottom surface and sidewalls of the trench, wherein a top/bottom portion of the film formed on the upper surface and the bottom surface and a sidewall portion of the film formed on the sidewalls are given different chemical resistance properties by bombardment of a plasma excited by applying voltage between two electrodes between which the substrate is place in parallel to the two electrodes; and substantially removing either one of but not both of the top/bottom portion and the sidewall portion of the film by wet etching which removes the one of the top/bottom portion and the sidewall portion of the film more predominantly than the other according to the different chemical resistance properties.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.