Electrical properties of photoanodically generated thin oxide films on n-GaN

Rotter, Thomas; Ferretti, R.; Mistele, D.; Fedler, F.; Klausing, H.; Stemmer, J.; Semchinova, O.; Aderhold, J.; Graul, J.

doi:10.1016/s0022-0248(01)01288-x

Cited by 13 publications

(6 citation statements)

References 7 publications

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“…The upper dark curve belongs to the spectra from the dark area between the source and gate. The relative nitrogen peak is much lower in this case The recessing was done softly by photoelectrochemical (PEC) procedures, which are discussed in previous publications [12,13]. The resulting transconductances g m of both structures, one on a recessed area and the other one conventionally processed, is given in Fig.…”

Section: Resultsmentioning

confidence: 78%

Influence of Process Technology on DC-Performance of GaN-Based HFETs

Mistele

Rotter

Bougrioua³

et al. 2002

phys. stat. sol. (a)

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This work reports on the influence of the surface and the gate length on the performance of AlGaN/GaN based Hetero Field Effect Transistors (HFETs). Differently NH4Sx treated surfaces result in variation of the drain current IDmax of more then 100%. Gate recessing by photoelectrochemical treatment changes the threshold voltage Vth but affects the drain current little. Next, the reduction of the gate length increases the IDmax further by more than 60%. The IDmax values for the transistors are 350 mA mm—1 for the NH4Sx‐treated, 850 mA for the untreated, and 1.43 A mm—1 for the one with a 0.2 μm gate length. The corresponding transconductances gm are 66, 150, and 280 mS mm—1, respectively. Surface analysis with Auger Electron Spectroscopy (AES) and contact characterization (TLM) reveals, that the NH4Sx treatment removes the native oxide and increases the contact resistance as well. Therefore we attribute the increase of IDmax and gm mainly to a beneficial behavior of gallium‐oxide at the surface on the sheet carrier density nS of the 2DEG at the heterointerface.

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Section: Resultsmentioning

confidence: 78%

Influence of Process Technology on DC-Performance of GaN-Based HFETs

Mistele

Rotter

Bougrioua³

et al. 2002

phys. stat. sol. (a)

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“…44 This is necessary to prevent dissolution of the relatively reactive oxide layer. Alternatively, the work of Rotter et el [38][39][40] on GaN and AlGaN suggests that (photo)anodic oxidation might be an interesting approach to making dielectric oxide on SiC (possibly with a low density of interface states) for device applications.…”

Section: Discussionmentioning

confidence: 99%

Electrochemical Growth of Micrometer-Thick Oxide on SiC in Acidic Fluoride Solution

et al. 2009

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Anodic polarization of SiC at modest potential in dilute fluoride solution of pH 3 surprisingly gives rise to the growth of micrometer-thick surface layers, clearly revealed with scanning electron microscopy. The reaction occurs at p-type SiC in the dark and at n-type SiC under (supra)bandgap illumination. The surface layer was shown by Rutherford backscattering spectrometry (RBS) to consist of silicon dioxide and to contain excess oxygen. Elastic recoil detection (ERD) indicated only a low level of carbon and fluoride in the layer but a considerable content of hydrogen. The growth kinetics was characterized in situ by spectroscopic ellipsometry and electrical impedance spectroscopy. The results suggest the formation of a duplex layer: a thin inner dielectric oxide and a thick hydrated outer oxide. The latter must have a considerable degree of porosity to allow diffusion/migration of reactants and products during oxide growth.

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“…GaN has received great attention for applications in optoelectronic and electronic devices due to its direct and wide band-gap properties. 1 Studies of the GaN metal-insulatorsemiconductor system have focused on reducing the interface state density ͑D it ͒, and these efforts can be classified into four groups: (i) deposited amorphous SiO 2 , 2 Si 3 N 4 , 3 and high-k Ta 2 O 5 ; 4 (ii) epitaxially grown AlN, 5 Gd 2 O 3 , 6 and Ga 2 O 3 ͑Gd 2 O 3 ͒; 7 (iii) native oxide by oxidation of GaN surface using thermal, 8,9 photoelectrochemical, [10][11][12] remote O 2 / He plasma, 13 and N 2 O / He plasma methods; 14 and (iv) gate stacks such as SiO 2 /Si 3 N 4 / SiO 2 (ONO). 15 In previous studies, 16,17 device-quality Si-SiO 2 interfaces and dielectric bulk film of SiO 2 were prepared using a twostep process: (i) remote plasma-assisted oxidation (RPAO) to form a superficially thin interfacial oxide ͑ϳ0.6 nm͒ and (ii) remote plasma-enhanced chemical vapor deposition to deposit the SiO 2 film.…”

Section: Introductionmentioning

confidence: 99%

Low-temperature preparation of GaN-SiO2 interfaces with low defect density. II. Remote plasma-assisted oxidation of GaN and nitrogen incorporation

Bae

Lucovsky

2004

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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Low-temperature remote plasma-assisted oxidation and nitridation processes for interface formation and passivation have been extended from Si and SiC to GaN. The initial oxidation kinetics and chemical composition of thin interfacial oxide were determined from analysis of on-line Auger electron spectroscopy features associated with Ga, N, and O. The plasma-assisted oxidation process is self-limiting with power-law kinetics similar to those for the plasma-assisted oxidation of Si and SiC. Oxidation using O 2 / He plasma forms nearly pure GaO x , and oxidation using 1% N 2 O in N 2 forms GaO x N y with small nitrogen content, ϳ4-7 at. %. The interface and dielectric layer quality was investigated using fabricated GaN metal-oxide-semiconductor capacitors. The lowest density of interface states was achieved with a two-step plasma-assisted oxidation and nitridation process before SiO 2 deposition.

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Electrical properties of photoanodically generated thin oxide films on n-GaN

Cited by 13 publications

References 7 publications

Influence of Process Technology on DC-Performance of GaN-Based HFETs

Influence of Process Technology on DC-Performance of GaN-Based HFETs

Electrochemical Growth of Micrometer-Thick Oxide on SiC in Acidic Fluoride Solution

Low-temperature preparation of GaN-SiO2 interfaces with low defect density. II. Remote plasma-assisted oxidation of GaN and nitrogen incorporation

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