Methods of forming trench isolation regions having recess-inhibiting layers therein that protect against overetching
US6461937B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 7, 2000 |
| Grant date | Oct 8, 2002 |
| Priority date | — |
| Expiry date | Jan 7, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76224
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Methods of forming trench isolation regions include the steps of forming a semiconductor substrate having a trench therein and a masking layer thereon extending adjacent the trench. The masking layer may comprise silicon nitride. A recess-inhibiting layer is then formed on a sidewall of the trench and on a sidewall of the masking layer. Next, a stress-relief layer is formed on the recess-inhibiting layer. This stress-relief layer extends opposite the sidewall of the trench and opposite the sidewall of the masking layer and may comprise silicon nitride. The trench is then filled with a trench isolation layer. A sequence of planarization or etch-back steps are then performed to remove the masking layer and also align an upper surface of the trench isolation layer with a surface of the substrate. At least a portion of the masking layer is removed using a first etchant (e.g., phosphoric acid) that selectively etches the masking layer and the stress-relief layer at faster rates than the first recess-inhibiting layer. The recess-inhibiting layer is formed directly on a sidewall of the masking layer in order to limit the extent to which the outer surfaces of the stress-relief layer are ex…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.