Method for selectivity enhancement during dry plasma etching
US9666447B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 22, 2015 |
| Grant date | May 30, 2017 |
| Priority date | — |
| Expiry date | Oct 22, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/0337
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of etching a layer on a substrate is described. The method includes disposing a substrate having a heterogeneous layer composed of a first material and a second material in a processing space of a plasma processing system, wherein the heterogeneous layer has an initial upper surface exposing the first material and the second material to a plasma environment in the processing space, and performing a modulated plasma etching process to selectively remove the first material at a rate greater than removing the second material. The modulated plasma etching process includes a modulation cycle that preferentially reacts an etchant with the first material during a first phase of the modulation cycle, and differentially adheres a passivant on the second material relative to the first material during a second phase of the modulation cycle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.