scholarly journals Mechanism of Defects and Electrode Structure on the Performance of AlN-based Metal Semiconductor Metal Detectors

2021 ◽  
Author(s):  
Guanghui Li ◽  
PengBo Wang ◽  
XinRan He ◽  
YuLong Meng ◽  
Feng Liang ◽  
...  
Keyword(s):  
Response Time ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Electrode Structure ◽  
Detector Performance ◽  
Zero Bias ◽  
Detector Electrode ◽  
Metal Semiconductor Metal ◽  
Finger Width ◽  
Metal Detectors

Abstract We used the metal-organic chemical vapor deposition(MOCVD) method to grow AlN material on a c-plane sapphire substrate and fabricate an AlN-based metal-semiconductor-metal (MSM) detector. Analyzing the influence mechanism of different dislocation densities in AlN materials and detector electrode structure on the detector performance, it was found that the lower the dislocations can effectively reduce the dark current of the detector under zero bias voltage, and help improve the performance of the detector. The study also found that when the finger spacing of the detector remained the same and the finger width increased, the efficiency of the detector decreased, while the response time of the detector increased, when the finger width of the detector electrodes remained unchanged and the finger spacing increased, the response time of the detector increased. Therefore, the electrode finger width and finger spacing must be compromised in the design of the electrode structure to improve the performance of the AlN-based MSM detector.

Current Characteristics of AlGaN/AlN Ultraviolet Photodetector with Metal-Semiconductor-Metal Structure

2013 ◽  
Vol 300-301 ◽  
pp. 1285-1288
Author(s):  
Li Zen Hsieh ◽  
Jun Yan Chang
Keyword(s):  
Reference Sample ◽  
Schottky Contact ◽  
Chemical Vapor ◽  
Metal Structure ◽  
Organic Chemical ◽  
Ultraviolet Photodetector ◽  
Metal Semiconductor Metal ◽  
Current Characteristics ◽  
Dimensional Electron Gas ◽  
Gan Heterostructure

An AlGaN/AlN ultraviolet photodetector with metal-semiconductor-metal structure is fabricated on n type 4H-SiC substrate, which is conventionally epitaxial by metal-organic chemical vapor deposition (MOCVD). The MSM structure is composed of two interdigitated fingers usually formed by Schottky contact which deposited metal with high work function metal by e-beam metallization and thermal evaporator on high resistance layers. This type of MSM has potential advantages, including ultra low dark current because of its rectifying contacts. The current Characteristics are revealed in this paper. A reference sample of AlGaN/GaN heterostructure with two-dimensional electron gas (2DEG) is also fabricated for comparision.

Metal-Semiconductor-Metal Ultraviolet Photodiodes Fabricated on Bulk GaN Substrate

2014 ◽  
Vol 986-987 ◽  
pp. 160-163
Author(s):  
Feng Xie ◽  
Guo Feng Yang ◽  
Jun Wang ◽  
Guo Sheng Wang ◽  
Man Song ◽  
...  
Keyword(s):  
High Temperature ◽  
Dark Current ◽  
Defect Density ◽  
Chemical Vapor ◽  
Mapping Technique ◽  
Organic Chemical ◽  
Rejection Ratio ◽  
Metal Semiconductor Metal ◽  
Bulk Gan ◽  
Metal Organic

We report the demonstration of a GaN-based planar metal-semiconductor-metal (MSM) ultraviolet photodetector (PD). The MSM PD with semitransparent interdigitated Schottky electrodes is fabricated on low-defect-density GaN homoepitaxial layer grown on bulk GaN substrate by metal-organic chemical vapor deposition. The dislocation density of the GaN homo-epilayer characterized by cathodoluminescence mapping technique is ~5×106 cm−2. The PD exhibits a low dark current density of ~4.1×10−10 A/cm2 and a high UV-to-visible rejection ratio up to 5 orders of magnitude at room temperature under 10 V bias. Even at a high temperature of 425 K, the dark current of the PD at 10 V is still <1×10−9 A/cm2 with a reasonable UV-to-visible rejection ratio more than 3×104, indicating that such kind of PDs are suitable for high temperature operation.

Structural and electronic properties of defects in semiconductors

1995 ◽  
Vol 53 ◽  
pp. 4-5
Author(s):  
J.L. Batstone
Keyword(s):  
Semiconductor Device ◽  
Chemical Vapor ◽  
Misfit Strain ◽  
Organic Chemical ◽  
Extended Defects ◽  
Transmission Electron ◽  
Semiconductor Thin Films ◽  
Wide Range ◽  
Metal Organic ◽  
Film Substrate

The development of growth techniques such as metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy during the last fifteen years has resulted in the growth of high quality epitaxial semiconductor thin films for the semiconductor device industry. The III-V and II-VI semiconductors exhibit a wide range of fundamental band gap energies, enabling the fabrication of sophisticated optoelectronic devices such as lasers and electroluminescent displays. However, the radiative efficiency of such devices is strongly affected by the presence of optically and electrically active defects within the epitaxial layer; thus an understanding of factors influencing the defect densities is required.Extended defects such as dislocations, twins, stacking faults and grain boundaries can occur during epitaxial growth to relieve the misfit strain that builds up. Such defects can nucleate either at surfaces or thin film/substrate interfaces and the growth and nucleation events can be determined by in situ transmission electron microscopy (TEM).

{10} edge dislocations in YSZ films grown on (100)MgO by PLD

1994 ◽  
Vol 52 ◽  
pp. 530-531
Author(s):  
Jason R. Heffelfinger ◽  
C. Barry Carter
Keyword(s):  
Thin Films ◽  
Semiconductor Lasers ◽  
Vapor Deposition ◽  
Substrate Surface ◽  
Laser System ◽  
Average Energy ◽  
Target Material ◽  
Chemical Vapor ◽  
Buffer Layers ◽  
Organic Chemical

Yttria-stabilized zirconia (YSZ) is currently used in a variety of applications including oxygen sensors, fuel cells, coatings for semiconductor lasers, and buffer layers for high-temperature superconducting films. Thin films of YSZ have been grown by metal-organic chemical vapor deposition, electrochemical vapor deposition, pulse-laser deposition (PLD), electron-beam evaporation, and sputtering. In this investigation, PLD was used to grow thin films of YSZ on (100) MgO substrates. This system proves to be an interesting example of relationships between interfaces and extrinsic dislocations in thin films of YSZ.In this experiment, a freshly cleaved (100) MgO substrate surface was prepared for deposition by cleaving a lmm-thick slice from a single-crystal MgO cube. The YSZ target material which contained 10mol% yttria was prepared from powders and sintered to 85% of theoretical density. The laser system used for the depositions was a Lambda Physik 210i excimer laser operating with KrF (λ=248nm, 1Hz repetition rate, average energy per pulse of 100mJ).

TEM study of very thin InGaAsP layers grown by liquid-phase epitaxy

1990 ◽  
Vol 48 (4) ◽  
pp. 672-673
Author(s):  
N.A. Bert ◽  
A.O. Kosogov
Keyword(s):  
Liquid Phase ◽  
Liquid Phase Epitaxy ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Dark Field ◽  
Organic Chemical ◽  
Simple Liquid ◽  
Cross Sectional ◽  
Conventional Procedure ◽  
Double Heterostructures

The very thin (<100 Å) InGaAsP layers were grown not only by molecular beam epitaxy and metal-organic chemical vapor deposition but recently also by simple liquid phase epitaxy (LPE) technique. Characterization of their thickness, interfase abruptness and lattice defects is important and requires TEM methods to be used.The samples were InGaAsP/InGaP double heterostructures grown on (111)A GaAs substrate. The exact growth conditions are described in Ref.1. The salient points are that the quarternary layers were being grown at 750°C during a fast movement of substrate and a convection caused in the melt by that movement was eliminated. TEM cross-section specimens were prepared by means of conventional procedure. The studies were conducted in EM 420T and JEM 4000EX instruments.The (200) dark-field cross-sectional imaging is the most appropriate TEM technique to distinguish between individual layers in 111-v semiconductor heterostructures.

High Breakdown Voltage GaN HEMT Device Fabricated on Self-Standing GaN Substrate

2013 ◽  
Vol 347-350 ◽  
pp. 1535-1539
Author(s):  
Jian Jun Zhou ◽  
Liang Li ◽  
Hai Yan Lu ◽  
Ceng Kong ◽  
Yue Chan Kong ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Breakdown Voltage ◽  
Oxygen Plasma ◽  
Cutoff Frequency ◽  
Chemical Vapor ◽  
Current Gain ◽  
Organic Chemical ◽  
Oxygen Plasma Treatment ◽  
Gan Hemt ◽  
High Breakdown Voltage

In this letter, a high breakdown voltage GaN HEMT device fabricated on semi-insulating self-standing GaN substrate is presented. High quality AlGaN/GaN epilayer was grown on self-standing GaN substrate by metal organic chemical vapor deposition. A 0.8μm gate length GaN HEMT device was fabricated with oxygen plasma treatment. By using oxygen plasma treatment, gate forward working voltage is increased, and a breakdown voltage of more than 170V is demonstrated. The measured maximum drain current of the device is larger than 700 mA/mm at 4V gate bias voltage. The maximum transconductance of the device is 162 mS/mm. In addition, high frequency performance of the GaN HEMT device is also obtained. The current gain cutoff frequency and power gain cutoff frequency are 19.7 GHz and 32.8 GHz, respectively. A high fT-LG product of 15.76 GHzμm indicating that homoepitaxy technology is helpful to improve the frequency performance of the device.

scholarly journals Laser‐Assisted Metal–Organic Chemical Vapor Deposition of Gallium Nitride

2021 ◽  
Vol 15 (6) ◽  
pp. 2170024
Author(s):  
Yuxuan Zhang ◽  
Zhaoying Chen ◽  
Kaitian Zhang ◽  
Zixuan Feng ◽  
Hongping Zhao
Keyword(s):  
Gallium Nitride ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

scholarly journals Noble Metals for Modern Implant Materials: MOCVD of Film Structures and Cytotoxical, Antibacterial, and Histological Studies

Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 851
Author(s):  
Svetlana I. Dorovskikh ◽  
Evgeniia S. Vikulova ◽  
Elena V. Chepeleva ◽  
Maria B. Vasilieva ◽  
Dmitriy A. Nasimov ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Noble Metals ◽  
Mononuclear Cells ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Ti Alloy ◽  
Peripheral Blood Mononuclear ◽  
Histological Studies

This work is aimed at developing the modification of the surface of medical implants with film materials based on noble metals in order to improve their biological characteristics. Gas-phase transportation methods were proposed to obtain such materials. To determine the effect of the material of the bottom layer of heterometallic structures, Ir, Pt, and PtIr coatings with a thickness of 1.4–1.5 μm were deposited by metal–organic chemical vapor deposition (MOCVD) on Ti6Al4V alloy discs. Two types of antibacterial components, namely, gold nanoparticles (AuNPs) and discontinuous Ag coatings, were deposited on the surface of these coatings. AuNPs (11–14 nm) were deposited by a pulsed MOCVD method, while Ag films (35–40 nm in thickness) were obtained by physical vapor deposition (PVD). The cytotoxic (24 h and 48 h, toward peripheral blood mononuclear cells (PBMCs)) and antibacterial (24 h) properties of monophase (Ag, Ir, Pt, and PtIr) and heterophase (Ag/Pt, Ag/Ir, Ag/PtIr, Au/Pt, Au/Ir, and Au/PtIr) film materials deposited on Ti-alloy samples were studied in vitro and compared with those of uncoated Ti-alloy samples. Studies of the cytokine production by PBMCs in response to incubation of the samples for 24 and 48 h and histological studies at 1 and 3 months after subcutaneous implantation in rats were also performed. Despite the comparable thickness of the fibrous capsule after 3 months, a faster completion of the active phase of encapsulation was observed for the coated implants compared to the Ti alloy analogs. For the Ag-containing samples, growth inhibition of S. epidermidis, S. aureus, Str. pyogenes, P. aeruginosa, and Ent. faecium was observed.

scholarly journals Growth-Etch Metal–Organic Chemical Vapor Deposition Approach of WS2 Atomic Layers

ACS Nano ◽  
2020 ◽  
Author(s):  
Assael Cohen ◽  
Avinash Patsha ◽  
Pranab K. Mohapatra ◽  
Miri Kazes ◽  
Kamalakannan Ranganathan ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition
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