Relationship between Excess Ga and Residual Oxides in Amorphous GaN Films Deposited by Compound Source Molecular Beam Epitaxy

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The low‐temperature deposition of AlN films by compound‐source molecular‐beam epitaxy (CS‐MBE) technique was studied. AlN powder was used as the source and no additional nitrogen source was introduced during the deposition. X‐ray photoelectron spectroscopy (XPS) results show that Al‐N bonds were formed in the deposited films. It was clarified that the nitrogen atoms were supplied to the substrate from the AlN source and that the oxygen concentration in the deposited AlN films depended on the residual oxygen concentration in the AlN powder used as the source. The breakdown electric field of the AlN film was over 4.2 MV/cm, which indicates that the films deposited at a low temperature of less than 300 °C can be applied as the insulator in GaN‐based electroluminescent devices. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Section: Discussionmentioning

confidence: 89%

“…Here, GaN powder was used as the source material and no additional nitrogen source was introduced during the growth. Part of the GaN powder was sublimated although part of it was decomposed [6]. The possibility of AlN growth by CS-MBE is a very attractive proposition for the fabrication of GaNbased light-emitting devices with low process temperatures.…”

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confidence: 99%

Fabrication of AlN films at low temperature by CS‐MBE technique

Honda

Watanabe

Sugimoto

et al. 2008

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“…A nearband-edge emission was observed from the spectra of hexagonal GaN films deposited on (0001)6H-SiC substrates, although a strong blue band emission was also observed. This blue band emission is due to the excess Ga and oxygen impurities in the deposited films [6]. The GaN films on the glass templates were also deposited under the same conditions as those in the case of the GaN Films on the SiC substrates.…”

Section: Resultsmentioning

confidence: 99%

Photoluminescence spectra of GaN films grown at low temperature by compound‐source molecular beam epitaxy

Honda

Sawada

Kobayashi

et al. 2006

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The photoluminescence spectra of GaN films deposited by compound-source molecular beam epitaxy (CS-MBE) at 450 °C are reported. A near band-edge emission was observed from the GaN layers grown on (0001) 6H-SiC substartes by CS-MBE at 18 K. The cathodoluminescence spectra of the deposited films and GaN powders were also observed at 20 K. The emission intensity per film thickness of the deposited films is roughly the same as that of GaN powders. Electroluminescent devices were fabricated using the deposited films, and a UV light emission was observed from these devices.

“…No signals corresponding to metallic gallium were observed in the Ga 2p XPS spectra. This is due to the oxidation of excess Ga in air [3]. The oxygen concentration became lower as the GaN cell temperature was decreased, which indicates the reduction of excess Ga during the deposition.…”

Section: Oxygen Concentration Dependence On Gan Cell Temperaturementioning

confidence: 99%

“…Although the molecular species created during the deposition are unknown at present, some GaN is sublimated and some is decomposed [2]. The reduction of excess Ga is one of the crucial issues for the deposition of GaN by CS-MBE technique [3].In this study, GaN-based thin-film electroluminescent devices (TF-ELDs) operating in UV spectral region and fabricated on Al substrates are reported. We find that the cell temperature of the GaN compound source is one of the key factors for reducing the excess Ga in the films during the deposition.…”

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confidence: 99%

Fabrication of GaN‐based electroluminescent devices on Al substrates and their application to red, green and blue pixels for flat‐panel displays

Sugimoto

Egawa

Arai

et al. 2007

Self Cite

PACS 78.60. Fi, 81.05.Ea, 81.15.Hi, 85.60.Jb GaN-based thin-film electroluminescent devices (TF-ELDs) operating in the UV spectral region were fabricated on Al substrates. GaN films were deposited by compound-source molecular beam epitaxy (CS-MBE) technique. During the deposition, the cell temperature of the GaN compound source is one of the key factors for reducing the excess Ga in the films. The UV light emission (peak wavelength 375 nm) corresponding to the near-band-edge emission of hexagonal GaN was observed from GaN-based TF-ELDs. Furthermore, red, green and blue (RGB) lighting pixels were fabricated using UV GaN-based TF-ELDs in combination with RGB phosphors. GaN deposited at low temperature on low-cost substrates, such as silica glass and aluminum, is effective for low-cost fabrication requirement. Compound-source molecular beam epitaxy (CS-MBE) [1] was very useful for low-temperature deposition [2]. GaN powder is used as a source and no additional nitrogen source is introduced. Although the molecular species created during the deposition are unknown at present, some GaN is sublimated and some is decomposed [2]. The reduction of excess Ga is one of the crucial issues for the deposition of GaN by CS-MBE technique [3].In this study, GaN-based thin-film electroluminescent devices (TF-ELDs) operating in UV spectral region and fabricated on Al substrates are reported. We find that the cell temperature of the GaN compound source is one of the key factors for reducing the excess Ga in the films during the deposition. We also propose red, green and blue (RGB) pixels fabricated on GaN-based TF-ELDs for excitation by UV light emissions.