Methods for forming semiconductor structures with buried isolation collars and semiconductor structures formed by these methods
US7811881B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 2008 |
| Grant date | Oct 12, 2010 |
| Priority date | — |
| Expiry date | Nov 4, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D1/665
Abstract
A semiconductor structure including a trench formed in a substrate and a buried isolation collar that extends about sidewalls of the trench. The buried isolation collar is constituted by an insulator formed from a buried porous region of substrate material. The porous region is formed from a buried doped region defined using masking and ion implantation or by masking the trench sidewalls and using dopant diffusion. Advantageously, the porous region is transformed to an oxide insulator by an oxidation process. The semiconductor structure may be a storage capacitor of a memory cell further having a buried plate about the trench and a capacitor node inside the trench that is separated from the buried plate by a node dielectric formed on the trench sidewalls.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.