Browse Prior Art Database

Method for Removing Oxidation Barrier Films

IP.com Disclosure Number: IPCOM000041894D
Original Publication Date: 1984-Mar-01
Included in the Prior Art Database: 2005-Feb-03
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Koburger, CW: AUTHOR [+4]

Abstract

The article describes a method for removing oxidation barrier films from semiconductor structures using dry etching techniques. Oxidation barrier films are used to mask areas which have to be protected during oxidation steps. These films are usually composed of a silicon oxynitride layer or a composite structure made of a SiO2 layer covered by either an Si3N4 or an SiOXNY layer. After the oxidation of the unmasked regions, the oxidation barrier films are presently removed using a sequence of etching steps which are preselected for the particular film to be removed. For example, if the top surface layer of the film is covered by SiO2 or an oxygen-rich silicon oxynitride layer, then a buffered HF acid etch is used to remove this surface layer.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 81% of the total text.

Page 1 of 1

Method for Removing Oxidation Barrier Films

The article describes a method for removing oxidation barrier films from semiconductor structures using dry etching techniques. Oxidation barrier films are used to mask areas which have to be protected during oxidation steps. These films are usually composed of a silicon oxynitride layer or a composite structure made of a SiO2 layer covered by either an Si3N4 or an SiOXNY layer. After the oxidation of the unmasked regions, the oxidation barrier films are presently removed using a sequence of etching steps which are preselected for the particular film to be removed. For example, if the top surface layer of the film is covered by SiO2 or an oxygen-rich silicon oxynitride layer, then a buffered HF acid etch is used to remove this surface layer. If Si3N4 is used in the barrier structure, then hot phosphoric acid is used to remove this film. If there is a pad thermal oxide, underneath the nitride layer, it is removed with the use of buffered HF. This series of etching steps is used in order to fully remove nitrified regions of substrate silicon which can cause gate oxide degradation. Complete removal results in overetching of the desired thick oxide regions. The method described herein avoids the problems associated with the wet etching techniques mentioned above by using a sequence of dry etching processing steps for the removal of the oxidation barrier film. Following is a preferred sequence of steps:
a). Remove SiOXNY fro...