Photoinduced oxide film formation on <i>n</i>-type GaN surfaces using alkaline solutions

Rotter, Thomas; Mistele, D.; Stemmer, J.; Fedler, F.; Aderhold, J.; Graul, J.; Schwegler, V.; Kirchner, C.; Kamp, M.; Heuken, M.

doi:10.1063/1.126822

Cited by 93 publications

(58 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…30 It is generally understood that the wet oxidation rate is limited by the diffusion of OH − ions, as with PEC etching of n-GaN. 25,29,31,32 In our oxidation studies, however, we observed current variation with increasing UV light intensity. This indicated that the oxidation rate is mainly limited by the generation of holes.…”

Section: A Cyclic Voltammetry Measurement and Oxidation Ratecontrasting

confidence: 51%

See 1 more Smart Citation

Improvements of electronic and optical characteristics of n-GaN-based structures by photoelectrochemical oxidation in glycol solution

Shiozaki

Hashizume

2009

Journal of Applied Physics

View full text Add to dashboard Cite

Surface control of n-GaN was performed by applying a photoelectrochemical oxidation method in a glycol solution to improve the optical and electronic characteristics. The fundamental properties of the oxidation were investigated. The oxidation, chemical composition, and bonding states were analyzed by x-ray photoelectron spectroscopy and micro-Auger electron spectroscopy, in which confirmed the formation of gallium oxide on the surface. The oxide formation rate was about 8 nm/min under UV illumination of 4 mW/ cm 2 . After establishing the basic properties for control of n-GaN oxidation, the surface control technique was applied to achieve low-damage etching, enhancement of the photoluminescence intensity, and selective passivation of the air-exposed sidewalls in an AlGaN/GaN high electron mobility transistor wire structure. The capacitance-voltage measurement revealed the minimum interface-state density between GaN and anodic oxide to be about 5 ϫ 10 11 cm −2 eV −1 , which is rather low value for compound semiconductors.

show abstract

Section: A Cyclic Voltammetry Measurement and Oxidation Ratecontrasting

confidence: 51%

“…The positively biased GaN sample was oxidized in the glycol solution as follows: 25,26 2GaN + 6h + → 2Ga 3+ + N 2 ↑, ͑1͒…”

Section: Experimental Methodsmentioning

confidence: 99%

Improvements of electronic and optical characteristics of n-GaN-based structures by photoelectrochemical oxidation in glycol solution

Shiozaki

Hashizume

2009

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…During the photo-assisted electrochemical process, oxidation generally takes place at the n-GaN surface according to the following reaction equations 4,8) .…”

Section: 7)mentioning

confidence: 99%

“…6) Unlike the processes in alkaline solutions used the previous studies, 4,5) the present method enables us to form a thin oxide layer on the GaN surface with a nearly neutral condition in the solution, which is important to avoid unexpected etching reactions on the oxidized GaN surface during the electrochemical process.…”

mentioning

confidence: 99%

“…As an example of a wet process for GaN, Ohkubo 3) reported the anodic etching of n-type GaN films in a NaOH electrolyte. For oxidation, Rotter et al 4) carried out a photo-assisted electrochemical process on the n-GaN surface in KOH solution under potentiostatic control. Similarly, Mistele et al 5) fabricated and characterized AlGaN/GaN high electron mobility transistors in which photoanodically grown oxide layers were used as gate dielectrics.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Formation of Thin Native Oxide Layer on n-GaN by Electrochemical Process in Mixed Solution with Glycol and Water

Shiozaki

Sato

Hashizume

2007

jjap

View full text Add to dashboard Cite

In this paper, we report on the feasibility of oxidizing n-GaN by an electrochemical process in a mixture containing an aqueous solution of tartaric acid and propylene glycol. Photons generated by UV illumination were supplied at the electrolyte-GaN interface during the oxidation process. In the constant-voltage mode, X-ray photoelectron spectroscopy analysis revealed that relatively thick Ga oxide layer formed on the n-GaN surface. However, the oxide surface was very rough. In addition, we found metallic Ga components in the oxide layer or at the oxide-GaN interface for longer oxidation times. On the other hand, a thin Ga 2 O 3 layer with a smooth surface was grown by a constant-current process.

show abstract

Heterostructure Field Effect Transistor Types with Novel Gate Dielectrics

Mistele

Rotter

Bougrioua

et al. 2001

phys. stat. sol. (a)

Self Cite

View full text Add to dashboard Cite

In this paper we report on results obtained for different AlGaN/GaN heterostructure field effect transistors (HFET) applying a recently developed photooxidation technique. We have processed and characterized MOS-HFETs in which a photoanodic oxide, a PECVD deposited SiO 2 layer, or a combined stack of the photoanodic oxide followed by SiO 2 (tandem-approach) is used as gate dielectric. All tandem-MOS-HFET devices have in common a large gate voltage swing and a broad transconductance peak. Additionally, the leakage and gate currents are several orders of magnitude smaller than for the Schottky gate HFETs and are in the range of pA/mm. Tandem MOSH-FET devices achieved values of 465 mA/mm in enhancement mode and 46 mS/mm for the drain current I Dmax and transconductance g m , respectively. These values are about 50% (I Dmax ) and 15% (g m ) higher than for the HFETs processed on the same wafer. Thermal oxidation at 900 C for 15 min before SiO 2 deposition leads to a normally off transistor type.

show abstract

Photoinduced oxide film formation on n-type GaN surfaces using alkaline solutions

Cited by 93 publications

References 20 publications

Improvements of electronic and optical characteristics of n-GaN-based structures by photoelectrochemical oxidation in glycol solution

Improvements of electronic and optical characteristics of n-GaN-based structures by photoelectrochemical oxidation in glycol solution

Formation of Thin Native Oxide Layer on n-GaN by Electrochemical Process in Mixed Solution with Glycol and Water

Heterostructure Field Effect Transistor Types with Novel Gate Dielectrics

Contact Info

Product

Resources

About