Structural Evolution of Pd/GaN(0001) Films during Postannealing

Kim, Chong Cook; Kim, Weon Hyo; Je, Jung Ho; Kim, Dae Woo; Baik, Hong Koo; Lee, Sung Man

doi:10.1149/1.1391141

Cited by 13 publications

(5 citation statements)

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“…5. 11 The Ag contact also showed a weak sixfold symmetry after annealing at 300°C, as shown in Fig. However, for the Ag͑In͒ contact, the phi scans of Ag ͑200͒ reflections showed sixfold symmetry same as the hexagonal ͑0001͒ GaN epilayer, demonstrating that partially epitaxial growth was shown in Ag͑In͒ contact on p-GaN with crystallographic alignments of Ag ͑111͒//GaN ͑0001͒.…”

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confidence: 82%

Strain induced suppression of silver agglomeration of indium-containing silver contact

Jung¹,

Son

Song

et al. 2010

Applied Physics Letters

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The mechanism for thermally stable indium-containing silver [Ag(In)] Ohmic contact on p-type GaN has been investigated. The specific contact resistivity as low as 3.8×10−5 Ω cm2 and a high reflectance of 88.4% at a 460 nm wavelength were obtained by annealing Ag(0.5 wt % In) alloy contact at 450 °C in air ambient. The In atoms in Ag matrix made In–O chemical bonds, producing a tensile stress in the film. This compensated thermal compressive stress built in the Ag film. As a result, In atoms in Ag film play a role in preventing Ag contact from agglomeration, leading to high reflectance and good thermal stability.

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confidence: 82%

Strain induced suppression of silver agglomeration of indium-containing silver contact

Jung¹,

Son

Song

et al. 2010

Applied Physics Letters

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“…In order to investigate the interfacial reactions between Pd and p-GaN of the two samples after annealing, HRTEM was employed to characterize the interfacial microstructure and the inter-diffusion behavior at Pd/p-GaN interfaces, as shown in ing determined from region "A" and "B" are 2.748 Å and 3.187 Å, respectively, corresponding to that of Pd (2.750 Å) and GaN (3.189 Å), as reported elsewhere. 29 The interfacial intermixing layers were found at the Pd/p-GaN interface (indicated by "C") by the reaction between Pd and p-GaN after annealing, as marked with "d". The interplanar spacings at the interfacial intermixing layers, which would have an intermediate value between that of Pd and GaN, 29,30 are 2.979 Å and 3.019 Å for the RT-and HT-samples, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…29 The interfacial intermixing layers were found at the Pd/p-GaN interface (indicated by "C") by the reaction between Pd and p-GaN after annealing, as marked with "d". The interplanar spacings at the interfacial intermixing layers, which would have an intermediate value between that of Pd and GaN, 29,30 are 2.979 Å and 3.019 Å for the RT-and HT-samples, respectively. Obviously, the interfacial intermixing layer of HT-sample is thicker than that of RTsample, indicating that the desorption of the interfacial contamination enhances the reaction between Pd and p-GaN upon annealing and promotes the formation of Pd gallides.…”

Section: Resultsmentioning

confidence: 99%

Investigation of Electrical and Interfacial Properties of Improved Ohmic Contact on p-Type GaN

Liu

Huang

et al. 2019

ECS J. Solid State Sci. Technol.

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Ohmic contacts on p-GaN with Pd/Pt/Au metallization scheme deposited at room temperature and elevated temperature were prepared to study the effect of metal deposition temperature on the contact properties. The specific contact resistance decreased by the heat-treatment of the p-GaN sample in an ultra-high vacuum environment. The in-diffusion of Au atoms and out-diffusion of Pd atoms are further suppressed by the diffusion barrier layer deposited at elevated temperature. The interfacial microstructure shows that the formation of Pd gallides is enhanced. The improvement of the electrical properties is attributed to the reduction of effective Schottky barrier height at the Pd/p-GaN interface by the XPS analyze and calculation, due to the desorption of the surface carbon or oxide contaminations of p-GaN.

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“…Subsequent annealing at 973 K for 30 s led to the formation of a mixture of Ga 2 Pd 5 and Ga 5 Pd intermetallic compounds. [18] Grodzicki et al sputtered a 1.5 nm thick Pd layer on a defined GaN surface. Annealing at 823 and 1073 K initiated the formation of island-type conglomerates of GaPd 2 and GaPd, respectively.…”

Section: Introductionmentioning

confidence: 99%

“…For instance, Kim et al used electronic beam evaporation to deposit Pd on a GaN surface. Subsequent annealing at 973 K for 30 s led to the formation of a mixture of Ga 2 Pd 5 and Ga 5 Pd intermetallic compounds . Grodzicki et al sputtered a 1.5 nm thick Pd layer on a defined GaN surface.…”

Section: Introductionmentioning

confidence: 99%

Intermetallic GaPd₂ Thin Films for Selective Hydrogenation of Acetylene

Zimmermann

Siebert

Ibrahimkutty

et al. 2020

Zeitschrift anorg allge chemie

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The preparation of single‐phase and catalytically active GaPd2 coatings was accomplished via DC magnetron sputtering using an intermetallic sputter target. Thin and uniform layers were deposited on borosilicate glass, Si(111) and planar as well as micro‐structured stainless steel foils. The specimens were examined regarding their phase composition, film morphology and microstructure. Thin films of different layer thickness were catalytically characterized in the semi‐hydrogenation of acetylene, which was conducted at 473 K and a feed gas composition of 0.5 vol.% C2H2, 5 vol.% H2 as well as 50 vol.% C2H4 in helium. Pre‐reduction of the catalyst was found to be essential to enhance the catalytic selectivity. Sputtered GaPd2 showed a high selectivity of 73 % for the hydrogenation to ethylene at conversion levels above 80 %. The surface‐specific activity was strongly increased to 8.97 molacetylene·(A0·h)–1 compared to bulk‐ or nanoscale GaPd2 (1.93 and 0.30 molacetylene·(A0·h)–1, respectively) caused by the high specific surface area of the thin films.

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Structural Evolution of Pd/GaN(0001) Films during Postannealing

Cited by 13 publications

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Strain induced suppression of silver agglomeration of indium-containing silver contact

Strain induced suppression of silver agglomeration of indium-containing silver contact

Investigation of Electrical and Interfacial Properties of Improved Ohmic Contact on p-Type GaN

Intermetallic GaPd₂ Thin Films for Selective Hydrogenation of Acetylene

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Structural Evolution of Pd/GaN(0001) Films during Postannealing

Cited by 13 publications

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Strain induced suppression of silver agglomeration of indium-containing silver contact

Strain induced suppression of silver agglomeration of indium-containing silver contact

Investigation of Electrical and Interfacial Properties of Improved Ohmic Contact on p-Type GaN

Intermetallic GaPd2 Thin Films for Selective Hydrogenation of Acetylene

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Product

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Intermetallic GaPd₂ Thin Films for Selective Hydrogenation of Acetylene