Power trench capacitor compatible with deep trench isolation process
US10355072B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 24, 2017 |
| Grant date | Jul 16, 2019 |
| Priority date | — |
| Expiry date | Mar 16, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D84/811
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for forming a trench capacitor without an additional mask adder and the resulting device are provided. Embodiments include forming a buried implant layer over a substrate; forming an EPI layer over the buried implant layer; forming an oxide layer over the EPI layer; forming a nitride layer over the oxide layer; forming first and second trenches in the nitride layer, the oxide layer, the EPI layer, the buried implant layer and the substrate, the first trench being wider and deeper than the second trench; forming a dielectric layer in the trenches; forming a first polysilicon layer over the dielectric layer in the trenches; removing the first polysilicon layer and the dielectric layer above the EPI layer in the trenches and at a bottom of the first trench; and forming a second polysilicon layer filling the first trench and above the EPI layer in the second trench.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.