Visible Blind uv GaN Photovoltaic Detector Arrays Grown by rf Atomic Nitrogen Plasma MBE

1996 ◽  
Vol 449 ◽  
Author(s):  
J.M. Van Hove ◽  
P.P. Chow ◽  
R. Hickman ◽  
A.M. Wowchak ◽  
J.J. Klaassen ◽  
...  
Keyword(s):  
Ohmic Contacts ◽  
Molecular Beam ◽  
Contact Layer ◽  
Nitrogen Plasma ◽  
Atomic Nitrogen ◽  
Detector Arrays ◽  
Photovoltaic Detectors ◽  
Silicon Doped ◽  
Visible Blind ◽  
Photovoltaic Detector

ABSTRACTRF atomic nitrogen plasma molecular beam epitaxy (MBE) was used to deposit gallium nitride (GaN) p-i-n junction photovoltaic detectors on (0001) sapphire. The detectors consisted of a bottom contact layer n-type silicon doped to 5 × 1018 cm−3. The intrinsic layer was undoped and possessed an n-type background carrier concentration of 1 × 1016 cm−3. The top /p-GaN layer was doped with magnesium to give a Hall concentration of 5 × 1017 cm−3. The p-type GaN cathodoluminescence (CL) spectra showed a strong 372 nm emission level in contrast to the 430 nm level observed in MOCVD samples. These layers were fabricated into 1 × 10 element detector arrays using a chlorine-based reactive ion etch (RIE) and refractory metal ohmic contacts. Peak responsivity of 0.11 AAV on detectors without anti-reflection coating were obtained at the GaN bandedge of 360 nm. The ultraviolet (UV) to visible rejection ratio was greater than 103 − 104 and was accredited to the reduction of the yellow defect levels in MBE material. Preliminary results on AlxGa1−xN detectors with responsivity peaks at 313 and 343 nm are presented as well.

High Temperature GaN and AlGaN Photovoltaic Detectors for UV Sensing Applications

1997 ◽  
Vol 482 ◽  
Author(s):  
J. M. Van Hove ◽  
P. P. Chow ◽  
R. Hickman ◽  
J. J. Klaassen ◽  
A. M. Wowchak ◽  
...  
Keyword(s):  
Ohmic Contacts ◽  
Elevated Temperatures ◽  
Internal Quantum Efficiency ◽  
Spectral Characteristics ◽  
Bottom Layer ◽  
Nitrogen Plasma ◽  
Type Material ◽  
Sensing Applications ◽  
Photovoltaic Detectors ◽  
P Type

AbstractAlGaN photodiode detectors are grown on (0001) sapphire by RF atomic nitrogen plasma molecular beam epitaxy. Both individual detectors and 1 × 10 element arrays are fabricated. The individual detectors have active areas of 0.5 mm2, 1.0 mm2, and 2.0 mm2. Individual elements in the l × 10 detector arrays range in size from 250×250 μm to 450×450 μm. The detectors are fabricated using a chlorine-based reactive ion etch (RIE) and refractory metal ohmic contacts. At room temperature, GaN p-i-n photovoltaic detectors show peak responsivity at 360 nm as high as 0.198 A/W, corresponding to an internal quantum efficiency of 85%. These detectors also exhibit five orders of magnitude of rejection for radiation longer than 500 nm. The electrical and spectral characteristics of these detectors are examined at elevated temperatures. The short wavelength UV responsivity remains fairly constant at elevated temperatures, while the peak responsivity actually increases with increasing temperature. The smooth surface morphology of heavily doped p-type material grown by MBE makes possible diode structures with a p-type bottom layer. The effect of the spectrally broader p-type material in the photodiode responsivity will be discussed.

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.

Features of the Initial Stage of GaN Growth on Si(111) Substrates by Nitrogen-Plasma-Assisted Molecular-Beam Epitaxy

2018 ◽  
Vol 52 (12) ◽  
pp. 1529-1533 ◽  
Author(s):  
A. M. Mizerov ◽  
S. N. Timoshnev ◽  
M. S. Sobolev ◽  
E. V. Nikitina ◽  
K. Yu. Shubina ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Nitrogen Plasma ◽  
Initial Stage

THE STUDY OF Pd SCHOTTKY CONTACT ON POROUS GaN FOR UV METAL–SEMICONDUCTOR–METAL (MSM) PHOTODETECTORS

2007 ◽  
Vol 16 (04) ◽  
pp. 497-503 ◽  
Author(s):  
L. S. CHUAH ◽  
Z. HASSAN ◽  
H. ABU HASSAN
Keyword(s):  
Molecular Beam Epitaxy ◽  
Tensile Stress ◽  
Molecular Beam ◽  
Schottky Contact ◽  
Nitrogen Plasma ◽  
Porous Sample ◽  
Optical Studies ◽  
High Quality ◽  
Metal Semiconductor Metal ◽  
Msm Photodetectors

High quality unintentionally doped n-type GaN layers were grown on Si (111) substrate using AlN (about 200 nm) as buffer layer by radio frequency (RF) nitrogen plasma-assisted molecular beam epitaxy (MBE). This paper presents the structural and optical studies of porous GaN sample compared to the corresponding as-grown GaN. Metal–semiconductor–metal (MSM) photodiode was fabricated on the samples. For as-grown GaN-based MSM, the detector shows a sharp cut-off wavelength at 362 nm, with a maximum responsivity of 0.254 A/W achieved at 360 nm. For porous GaN MSM detector, a sharp cut-off wavelength at 360 nm with a maximum responsivity of 0.655 A/W was achieved at 359 nm. Both the detectors show a little decrease in responsivity in the UV spectral region. The MSM photodiode based on porous GaN shows enhanced (2×) magnitude of responsivity relative to the as-grown GaN MSM photodiode. Enhancement of responsivity can be attributed to the relaxation of tensile stress and reduction of surface pit density in the porous sample.

Atomic nitrogen doping in p-ZnSe molecular beam epitaxial growth with almost 100% activation ratio

1997 ◽  
Vol 71 (8) ◽  
pp. 1077-1079 ◽  
Author(s):  
K. Kimura ◽  
S. Miwa ◽  
C. G. Jin ◽  
L. H. Kuo ◽  
T. Yasuda ◽  
...  
Keyword(s):  
Epitaxial Growth ◽  
Nitrogen Doping ◽  
Molecular Beam ◽  
Atomic Nitrogen ◽  
Molecular Beam Epitaxial ◽  
Activation Ratio ◽  
Molecular Beam Epitaxial Growth

Electron Temperature Determination from Non-LTE Populations in a Nitrogen Plasma JET

1975 ◽  
Vol 30 (9) ◽  
pp. 1143-1155
Author(s):  
A. Catherinot ◽  
A. Sy
Keyword(s):  
Excited State ◽  
Pressure Range ◽  
Electronic Excitation ◽  
Plasma Jet ◽  
Nitrogen Plasma ◽  
Measured Data ◽  
Atomic Nitrogen ◽  
Plasma Model ◽  
Boltzmann Plot ◽  
Two Temperatures

Atomic nitrogen electronic state populations and electron density have been measured in a high power nitrogen plasma jet in the pressure range 50 < P (Torr) < 150. A Boltzmann plot of the excited state populations led to electronic excitation temperatures depending on the groups of levels considered. Low and high lying levels yielded excitation temperatures which differed up to 80% at P = 120 Torr. The measured data are analysed in the frame of a two-temperatures diffusiondominated plasma model

Sign in / Sign up

Export Citation Format

Share Document