Real-time, in situ infrared study of etching of Si(100) and (111) surfaces in dilute hydrofluoric acid solution

Michio Niwano, Taka Aki Miura, Yasuo Kimura, Ryo Tajima, Nobuo Miyamoto

Research output: Contribution to journalArticle

45 Citations (Scopus)

Abstract

The chemical nature of Si(100) and (111) surfaces during immersion in dilute hydrofluoric acid (HF) solution was investigated "in situ" and in real time using infrared absorption spectroscopy in the multiple internal reflection geometry. In dilute HF solution, the Si surface is not completely terminated with hydrogen, but may be covered in part with hydrogen-associated Si fluorides, such as SiH2(SiF) and SiH2F2. It is found that the hydrogen coverage of the surface depends on the HF concentration of the solution. At HF concentrations above 1%, the surface concentration of Si hydrides is reduced while that of Si fluorides is enhanced. We confirm that rinsing in water following HF immersion leads to complete hydrogen termination of the surface. Based on the present experimental results, we suggest that in dilute HF the Si surface is in chemical equilibrium with the solution to allow the coexistence of Si hydrides and Si fluorides on the surface.

Original languageEnglish
Pages (from-to)3708-3713
Number of pages6
JournalJournal of Applied Physics
Volume79
Issue number7
DOIs
Publication statusPublished - 1996 Apr 1

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'Real-time, in situ infrared study of etching of Si(100) and (111) surfaces in dilute hydrofluoric acid solution'. Together they form a unique fingerprint.

  • Cite this