Dry cleaning technology for removal of silicon native oxide employing hot NH3/NF3 exposure

被引：0

作者：

Ogawa, Hiroki ^{[1
,3
]}

Arai, Tomoharu ^{[1
]}

Yanagisawa, Michihiko ^{[2
]}

Ichiki, Takanori ^{[1
]}

Horiike, Yasuhiro ^{[2
]}

机构：

[1] Department of Materials Engineering, School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan

[2] Department of Electric and Electronic Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan

[3] Speedfam Co., Ltd., 2647 Hayakawa, Ayase, Kanagawa 252-1123, Japan

来源：

Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers | 2002年 / 41卷 / 08期

关键词：

Dry cleaning - Etching - Infrared spectroscopy - Reaction kinetics - Semiconducting films - Silica - X ray photoelectron spectroscopy;

D O I：

10.1143/jjap.41.5349

中图分类号：

学科分类号：

摘要：

A new dry cleaning technology for removal of silicon (Si) native oxides from contact holes employing a hot ammonium (NH3)/nitrogen trifluoride (NF3) mixture has been studied. The NH3/NF3 mixture heated at a high temperature in a quartz tube enabled etching of the silicon dioxide (SiO2) film placed in the downstream region. The mechanism of the etching reaction which was investigated using in-situ infrared spectroscopy and X-ray photoelectron spectroscopy analysis was revealed as follows: NF3 alone in the NH3/NF3 mixture was decomposed above 600°C, probably producing NFx (x = 1, 2) and fluorine atoms. These active species reacted with NH3, thereby generating ammonium hydrogen fluoride (NH4F · HF) and/or ammonium fluoride (NH4F) in the gas phase which are considered to be SiO2 etchants. The reaction of these molecules with SiO2 generated an ammonium hexafluorosilicate ((NH4)2SiF6) product on the Si surface which was liberated at a temperature above 70°C, leaving the hydrogen terminated surface. The application of this method to actual contact holes demonstrated successful removal of the Si native oxide grown on the Si surface at the hole bottom.

引用

页码：5349 / 5358