Estimation of activation energy and surface reaction mechanism of chlorine neutral beam etching of GaAs for nanostructure fabrication

C. Thomas, Y. Tamura, T. Okada, A. Higo, S. Samukawa

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)

Abstract

To understand the etching mechanisms of GaAs materials through the neutral beam etching (NBE) process developed in our laboratory, we investigated the effect of substrate temperature on etching conditions. The etch rate as a function of wafer temperature was found to increase with temperature. The apparent activation energy was calculated to be an average of about 8.6±1.4kJmol-1. However, as the vapour pressure of the etch product (GaClx) was above the chamber pressure, the etching mechanism was assumed to be temperature independent. It has been suggested that residual Ga23 oxide on the GaAs surface is responsible for the temperature dependence of the etch rate. A comparison with reactive ion etching (RIE) was done and a lower activation energy was calculated (4.0±0.3kJmol -1). We argue that etching of residual oxide on the GaAs surface is more efficient with RIE because of the energetic ions and ultraviolet photons. It should be noted that when substrate temperature was increased, the etching rate ratio between NBE and RIE decreased, suggesting a stronger effect of chemical etching on the etching mechanism.

Original languageEnglish
Article number275201
JournalJournal of Physics D: Applied Physics
Volume47
Issue number27
DOIs
Publication statusPublished - 2014 Jul 9

Keywords

  • GaAs
  • activation energy
  • neutral beam etching
  • reactive ion etching

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Acoustics and Ultrasonics
  • Surfaces, Coatings and Films

Fingerprint Dive into the research topics of 'Estimation of activation energy and surface reaction mechanism of chlorine neutral beam etching of GaAs for nanostructure fabrication'. Together they form a unique fingerprint.

Cite this