Low temperature plasmaless etching of silicon dioxide film using chlorine trifluoride gas with water vapor

Makoto Saito, Yoshinori Kataoka, Tetsuya Homma, Takao Nagatomo

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

The etching characteristics of silicon dioxide (SiO2) films using chlorine trifluoride (ClF3) gas with water (H2O) vapor, without using the gas discharge method, have been studied. When the sample was cooled to -50 °C, a high SiO2 etching rate of 400 nm/mix was obtained. On the basis of in situ Fourier transform infrared spectroscopic analysis for the vapor phase and for the sample surface, the etching mechanism of the high SiO2 etching rate was proposed. The mechanism consists of (i) adsorption of H2O onto the sample surface at low temperatures, (ii) hydrogen fluoride ion (HF2-) formation by the reaction of hydrogen fluoride (HF) with H2O, in which the HF is formed by the hydrolysis of ClF3, (iii) silicon tetrafluoride (SiF4) formation by the reaction of HF2- with Si in SiO2 networks, and (iv) desorption of SiF4 as a gas from the SiO2 surface. It has been confirmed that low temperature plasmaless etching using a ClF3/H2O gas mixture is effective for the removal of SiO2 films. In addition, the etch rate for polycrystalline silicon (poly-Si) can be controlled by changing the substrate temperature from 25 to -50 °C. This property allows for the sequential etching of native oxide and poly-Si films.

Original languageEnglish
Pages (from-to)4630-4632
Number of pages3
JournalJournal of the Electrochemical Society
Volume147
Issue number12
DOIs
Publication statusPublished - 2000 Dec

Fingerprint

Steam
Silicon Dioxide
Water vapor
Chlorine
chlorine
water vapor
Etching
Gases
Silica
etching
Hydrofluoric Acid
silicon dioxide
hydrofluoric acid
gases
Polysilicon
Hydrogen
Temperature
Spectroscopic analysis
spectroscopic analysis
gas discharges

ASJC Scopus subject areas

  • Electrochemistry
  • Surfaces, Coatings and Films
  • Surfaces and Interfaces

Cite this

Low temperature plasmaless etching of silicon dioxide film using chlorine trifluoride gas with water vapor. / Saito, Makoto; Kataoka, Yoshinori; Homma, Tetsuya; Nagatomo, Takao.

In: Journal of the Electrochemical Society, Vol. 147, No. 12, 12.2000, p. 4630-4632.

Research output: Contribution to journalArticle

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