Methods and apparatus for TMAH etching

Patent metadata

Field	Value
Publication number	US-8999850-B2
Application number	US-201113339797-A
Country	US
Kind code	B2
Filing date	Dec 29, 2011
Priority date	Dec 29, 2011
Publication date	Apr 7, 2015
Grant date	Apr 7, 2015

Abstract

Methods and apparatus for etching materials using tetramethylammonium hydroxide (TMAH) are described. The methods may involve including an additive when applying the TMAH to the material to be etched. The additive may be a gas, and in some situations may be clean dry air. The clean dry air may be provided with the TMAH to minimize or prevent the formation of hillocks in the etched structure. Apparatus for performing the methods are also described.

First claim

What is claimed is:

1. A method, comprising:
etching a trench in a crystalline semiconductor material disposed within an etching chamber by:
introducing tetramethylammonium hydroxide (TMAH) into the etching chamber during an etching period;
flowing clean dry air (CDA) into the etching chamber during at least part of the etching period;
mixing the TMAH and CDA together in a supply line coupled to said etching chamber to form an etchant comprising a mixture of the TMAH with the…

Assignees

• Yu Ying
• Loh Tien Choy
• Kam Shian Yeu
• St Microelectronics Pte Ltd

Inventors

• Yu Ying
• Loh Tien Choy
• Kam Shian Yeu

Classifications

• H10P50/644

  Electricity · mapped topic

• C09K13/00 Primary

  Chemistry & Metallurgy · mapped topic

• H01L21/30608

  Electricity · mapped topic