Halogen-free gas-phase silicon etch

Patent metadata

Field	Value
Publication number	US-9190290-B2
Application number	US-201414231180-A
Country	US
Kind code	B2
Filing date	Mar 31, 2014
Priority date	Mar 31, 2014
Publication date	Nov 17, 2015
Grant date	Nov 17, 2015

Abstract

A method of selectively dry etching silicon from patterned heterogeneous structures is described. The method optionally includes a plasma process prior to a remote plasma etch. The plasma process may use a biased plasma to treat some crystalline silicon (e.g. polysilicon or single crystal silicon) to form amorphous silicon. Subsequently, a remote plasma is formed using a hydrogen-containing precursor to form plasma effluents. The plasma effluents are passed into the substrate processing region to etch the amorphous silicon from the patterned substrate. By implementing biased plasma processes, the normally isotropic etch may be transformed into a directional (anisotropic) etch despite the remote nature of the plasma excitation during the etch process.

First claim

The invention claimed is:

1. A method of etching a substrate, the method comprising:
treating the substrate with a local plasma formed from an inert gas, wherein treating the substrate comprises transitioning a crystalline silicon portion of the substrate into an amorphous silicon portion of the substrate and wherein the local plasma is formed by applying a local plasma power to excite the local plasma; and
etching the amorphous silicon portion of the substrate, wherein etching…

Assignees

• Applied Materials Inc

Inventors

• Xue Jun
• Ying Chentsau
• Nemani Srinivas D

Classifications

• H10P50/268

  Electricity · mapped topic

• H10P50/242 Primary

  Electricity · mapped topic

• H10P50/283 Primary

  Electricity · mapped topic

• H01J37/32357

  Electricity · mapped topic

• H10D64/017

  Electricity · mapped topic