Method of etching a deep trench in a substrate and method of fabricating on-chip devices and micro-machined structures using the same
US6712983B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 2001 |
| Grant date | Mar 30, 2004 |
| Priority date | — |
| Expiry date | Aug 8, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/3065
- WIPO fieldMicro-structural and nano-technology
- WIPO sectorChemistry
Abstract
A method of etching a trench in a substrate using a dry plasma etch technique that allows precise control of lateral undercut. The method includes optionally forming at least one on-chip device or micro-machined structure in a surface of a silicon substrate, and covering the surface with a masking layer. A trench pattern is then imaged in or transferred to the masking layer for subsequent etching of the substrate. Upper portions of the trench are anisotropically etched in the substrate. The trench is then semi-anisotropically etched and isotropically etched in the substrate. By modifying isotropic etching time, a controlled lateral undercut can be achieved as the trench is etched vertically in the substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.