A study of the photoelectrochemical etching of n-GaN in H 3PO4 and KOH electrolytes

C. Heffernan, D. N. Buckley, C. O'Raifeartaigh

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

We review our work on the photoelectrochemical (PEC) etching characteristics of n-GaN in H3PO4 and KOH as a function of electrolyte concentration and applied potential. Linear sweep voltammograms showed current peaks in both acidic and basic solutions, which are attributed to the formation of a passivating oxide films. In both electrolytes, the etch rates were found to increase with increasing concentration reaching peak values at 3.0 mol dm-3 and then decrease at higher concentrations. Current time measurements at constant potential in conjunction with surface profilometric measurements of etch rate on partially masked electrodes gave similar results. A model is proposed to explain the concentration dependence of the PEC etch rate It is proposed that, that at low concentrations, the etch rate is reduced due to the formation of a passivating oxide film arising from the lower rate of dissolution. At high concentrations it is proposed that the etch rate is again reduced due to mass transport effects in these higher viscosity electrolytes.

Original languageEnglish
Title of host publicationState-of-the-Art Program on Compound Semiconductors (SOTAPOCS XLIII) -and- Nitride and Wide Bandgap Semiconductors for Sensors, Photonics, and Electronics VI
PublisherElectrochemical Society Inc.
Pages133-148
Number of pages16
Edition2
ISBN (Electronic)9781607685395
Publication statusPublished - 2006
Event43rd State-of-the-Art Program on Compound Semiconductors (SOTAPOCS XLIII)and Nitride and Wide Bandgap Semiconductors for Sensors, Photonics, and Electronics VI Symposium - 208th Meetingof the Electrochemical Society - Los Angeles, CA, United States
Duration: 16 Oct 200521 Oct 2005

Publication series

NameECS Transactions
Number2
Volume1
ISSN (Print)1938-5862
ISSN (Electronic)1938-6737

Conference

Conference43rd State-of-the-Art Program on Compound Semiconductors (SOTAPOCS XLIII)and Nitride and Wide Bandgap Semiconductors for Sensors, Photonics, and Electronics VI Symposium - 208th Meetingof the Electrochemical Society
Country/TerritoryUnited States
CityLos Angeles, CA
Period16/10/0521/10/05

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