P-type Mg-doped GaN grown by molecular beam epitaxy using ammonia as the nitrogen source

1995 ◽  
Vol 395 ◽  
Author(s):  
Z. Yang ◽  
L.K. Li ◽  
W.I. Wang
Keyword(s):  
Molecular Beam Epitaxy ◽  
Nitrogen Source ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
Luminescent Properties ◽  
Nitrogen Plasma ◽  
Organic Chemical ◽  
Hole Density ◽  
P Type ◽  
Mg Doped

ABSTRACTThe electrical and luminescent properties of Mg-doped GaN films grown by molecular beam epitaxy (MBE) using ammonia as the nitrogen source have been investigated. Due to their different growth environments, the Mg-doped GaN films grown by MBE using ammonia exhibited properties that were different from similar films grown by metal-organic chemical vapor deposition (MOCVD). It has been found that the introduction of positive charges during growth is important in the achievement of p-type Mg-doped GaN grown by MBE using ammonia. With the introduction of a moderate nitrogen plasma, we have achieved p-type Mg-doped GaN films with a hole density of 4×1017 cm−3 and a mobility of 15 cm2/V-s at room temperature.

p‐type CdSe grown by molecular beam epitaxy using a nitrogen plasma source

1994 ◽  
Vol 65 (4) ◽  
pp. 466-468 ◽  
Author(s):  
Takeo Ohtsuka ◽  
Junji Kawamata ◽  
Ziqiang Zhu ◽  
Takafumi Yao
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Plasma Source ◽  
Nitrogen Plasma ◽  
P Type

The Role of Nitrogen-Induced Localization and Defects in InGaAsN (? 2% N): Comparison of InGaAsN Grown by Molecular Beam Epitaxy and Metal-Organic Chemical Vapor Deposition

2001 ◽  
Vol 692 ◽  
Author(s):  
Steven R Kurtz ◽  
A. A. Allermana ◽  
J. F. Klem ◽  
R. M. Sieg ◽  
C. H. Seager ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Molecular Beam Epitaxy ◽  
Vapor Deposition ◽  
Molecular Beam ◽  
Minority Carrier ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Carrier Diffusion ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

AbstractNitrogen vibrational mode spectra, Hall mobilities, and minority carrier diffusion lengths are examined for InGaAsN (≈ 1.1 eV bandgap) grown by molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD). Independent of growth technique, annealing promotes the formation of In-N bonding, and lateral carrier transport is limited by large scale (Ęmean free path ) material inhomogeneities. Comparing solar cell quantum efficiencies for devices grown by MBE and MOCVD, we find significant electron diffusion in the MBE material (reversed from the hole diffusion occurring in MOCVD material), and minority carrier diffusion in InGaAsN cannot be explained by a “universal”, nitrogen-related defect.

Persistent Photoconductivity in p-Type GaN Epilayers and n-Type AlGaN/GaN Heterostructures

1996 ◽  
Vol 449 ◽  
Author(s):  
J. Z. Li ◽  
J. Y. Lin ◽  
H. X. Jiang ◽  
M. A. Khan ◽  
Q. Chen ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Persistent Photoconductivity ◽  
Dimensional Electron ◽  
Metal Organic ◽  
Dimensional Electron Gas ◽  
Gan Heterostructure ◽  
P Type ◽  
Organic Chemical Vapor Deposition

ABSTRACTPersistent photoconductivity (PPC) effect has been observed in p-type GaN epilayers grown both by metal-organic chemical vapor deposition (MOCVD) and reactive molecular beam epitaxy (MBE) as well as in a two-dimensional electron gas (2DEG) system formed by an AlGaN/GaN heterostructure grown by MOCVD. Its properties have been investigated at different conditions.

Si and Mg Doped Gan Layers Grown by Gas Source Molecular Beam Epitaxy Using Ammonia

1997 ◽  
Vol 482 ◽  
Author(s):  
N. Grandjean ◽  
J. Massies ◽  
M. Leroux
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
Light Emitting ◽  
X Ray ◽  
Sapphire Substrates ◽  
Gas Source ◽  
P Type ◽  
Mg Doped

AbstractThe growth of GaN layers was carried out on c-plane sapphire substrates by molecular beam epitaxy (MBE) using NH3. Undoped GaN layers were grown at 830°C with growth rates larger than 1 μm/h. Optical properties are characteristics of high quality GaN material and the linewidth of x-ray diffraction (0002) rocking curve is less than 350 arcsec. N- and p-type doping were achieved by using solid sources of Si and Mg. No post-growth annealing was needed to activate the Mg acceptors. As-grown GaN:Mg layers exhibit hole concentrations of 3×1017 cm−3and mobilities of 8 cm2/Vs at 300 K. Light emitting diodes (LEDs) based on GaN p-n homojunction have been processed. The turn on voltage is 3 V and the forward voltage is 3.7 V at 20 mA. The 300 K electroluminescence (EL) peaks at 390 nm.

Photocurrent Spectroscopy Investigations of Mg-Related Defects Levels in p-Type GaN

1999 ◽  
Vol 595 ◽  
Author(s):  
S. J. Chung ◽  
O. H. Cha ◽  
H. K. Cho ◽  
M. S. Jeong ◽  
C-H. Hong ◽  
...  
Keyword(s):  
Hole Concentration ◽  
Chemical Vapor ◽  
Nitrogen Atmosphere ◽  
Organic Chemical ◽  
Substitutional Site ◽  
Photocurrent Spectroscopy ◽  
Metal Organic ◽  
P Type ◽  
Two Peaks ◽  
Mg Doped

AbstractThe defect levels associated with Mg impurity in p-type GaN films were systematically investigated in terms of doping concentration by photocurrent spectroscopy. Mg-doped GaN samples were grown on sapphire substrate by metal organic chemical vapor deposition and annealed in nitrogen atmosphere at 850 for 10 minutes. At room temperature, PC spectra showed two peaks at 3.31 and 3.15 eV associated with acceptor levels formed at 300 and 142 meV above valence band in as grown samples. But, after the thermal annealing, PC spectra exhibited various additional peaks depending on the Mg concentration. In the GaN samples with Mg concentration around 6 7 1017 cm−3, we have observed PC peaks related to Mg at 3.31 as well as 3.02 eV and carbon acceptor at 3.17 eV. For moderately Mg doped GaN samples, i.e., the hole concentration p=3 4 1017 cm−3, additional peak was observed at around 0.9 eV which can be attributed to defects related to Ga vacancy. For relatively low Mg doped samples whose hole concentrations are 1 2 1017 cm−3, additional broad peak was observed at around 1.3 eV. This peak may be related to the yellow band luminescence. As the Mg concentration is increased, the concentration of Ga vacancies can be reduced because Mg occupies the substitutional site of Ga in GaN lattice. When the hole concentration is above 6 7 1017 cm−3, the yellow luminescence and Ga vacancy related peaks disappeared completely.

Low Resistance Ohmic Contact on p-type GaN Grown by Plasma-Assisted Molecular Beam Epitaxy

1996 ◽  
Vol 423 ◽  
Author(s):  
Myung C. Yoo ◽  
J. W. Lee ◽  
J. M. Myoung ◽  
K. H. Shim ◽  
K. Kim
Keyword(s):  
Molecular Beam Epitaxy ◽  
Ohmic Contacts ◽  
Doping Concentration ◽  
Molecular Beam ◽  
Plasma Source ◽  
Nitrogen Plasma ◽  
Specific Contact Resistance ◽  
Metal Bilayers ◽  
Auger Microscopy ◽  
P Type

AbstractOhmic contacts on p-type GaN have been investigated. High quality GaN epilayers on cplane sapphire were prepared using plasma-assisted molecular beam epitaxy that utilized an inductively coupled rf nitrogen plasma source and solid source beams. The resulting film thickness and the doping concentration of the grown samples were in the range of 0.7–1.35 μm and 1018 – 1020/cm3, respectively. The metallization consisted of high work function metal bilayers which included a combinations of 25 nm-thick Ni, Ti, Pt and/or Cr and 200 nm-thick Au on the highly p-doped GaN in a transmission line model pattern. Ohmic contacts were formed by alloying the bi-layers using rapid thermal annealing (RTA) at temperatures in the range of 300–700 °C for 1 min under nitrogen ambient. Current-voltage measurements showed that the specific contact resistance was as low as 1.2 × 10 −4 Ω–cm2 for the sample having 1.4 × 1020/cm3p-type doping concentration with a Cr/Au contact annealed at 500 °C for 1 min by RTA. Judging from the scanning Auger microscopy results and the glancing angle x-ray diffraction analysis, this resistance is attributed to Cr diffusion into the GaN layer.

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