Electrical Properties of Ni/GaN Schottky Contacts on High-Temperature Annealed GaN Surfaces

2009 ◽  
Vol 615-617 ◽  
pp. 959-962
Author(s):  
Ferdinando Iucolano ◽  
Fabrizio Roccaforte ◽  
Filippo Giannazzo ◽  
Salvatore di Franco ◽  
Giuseppe Moschetti ◽  
...  
Keyword(s):  
High Temperature ◽  
Schottky Contact ◽  
Schottky Contacts ◽  
Guard Ring ◽  
High Temperature Annealing ◽  
Electrical Behaviour ◽  
Power Devices ◽  
Recent Improvement ◽  
New Perspective ◽  
Density Of Interface States

The recent improvement of GaN material quality launched new perspective for its application in power devices. However, ion-implanted guard-ring edge terminations, necessary to improve the breakdown voltage, are not well developed as in SiC technology. Indeed, the effects of high-temperature annealing, required for the electrical activation of the implanted species in GaN, on the electrical behaviour of Schottky contact was not reported. In this work, the influence of high temperature annealing (1150-1200°C) on the surface morphology of GaN and on the electrical behaviour of Schottky contact was studied. Although the morphology of GaN surface did not substantially change after annealing, a worsening of the electrical behaviour of Schottky contact was observed. This latter was ascribed to the formation of a high density of interface states after annealing.

Process-Induced Defects in High-Purity GaAs

1982 ◽  
Vol 14 ◽  
Author(s):  
P. H. Campbell ◽  
O. Aina ◽  
B. J. Baliga ◽  
R. Ehle
Keyword(s):  
High Temperature ◽  
High Purity ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Deep Levels ◽  
Schottky Contacts ◽  
High Temperature Annealing ◽  
Order Of Magnitude ◽  
Transient Spectroscopy ◽  
Induced Defects

ABSTRACTHigh temperature annealing of Si 3 N4 and SiO2 capped high purity LPE GaAs is shown to result in a reduction in the surface carrier concentration by about an order of magnitude. Au Schottky contacts made on the annealed samples were found to have severely degraded breakdown characteristics. Using deep level transient spectroscopy, deep levels at EC–.58eV, EC–.785eV were detected in the SiO2, capped samples and EC–.62eV, EC–.728eV in the Si3N4 capped Samples while none was detected in the unannealed samples.The electrical degradations are explained in terms of compensation mechanisns and depletion layer recombination-generation currents due to the deep levels.

High Temperature Stable Titanium Carbide Ohmic and Schottky Contacts to SiC

1998 ◽  
Vol 512 ◽  
Author(s):  
C.-M. Zetterling ◽  
M. östling ◽  
L. Norin ◽  
U. Jansson
Keyword(s):  
High Temperature ◽  
Titanium Carbide ◽  
Schottky Diodes ◽  
Schottky Contact ◽  
Schottky Contacts ◽  
Knudsen Cell ◽  
Vacuum Furnace ◽  
Electrical Measurements ◽  
Low Resistivity

ABSTRACTEpitaxial titanium carbide is investigated as a low resistivity, high temperature stable Ohmic and Schottky contact to 4H and 6H SiC. The titanium carbide films were deposited at 500°C using co-evaporation of titanium (e-beam) and C60 (Knudsen cell) in a UHV system. Schottky diodes and TLM structures were fabricated on low and high doped SiC material respectively. The samples were annealed at 700 °C in a vacuum furnace, and electrical measurements were performed up to 300 °C.

Improvement in Electrical Performance of Schottky Contacts for High-Voltage Diode

2005 ◽  
Vol 483-485 ◽  
pp. 721-724 ◽  
Author(s):  
Tomonori Nakamura ◽  
Toshiyuki Miyanagi ◽  
Hidekazu Tsuchida ◽  
Isaho Kamata ◽  
Tamotsu Jikimoto ◽  
...  
Keyword(s):  
High Temperature ◽  
Schottky Barrier ◽  
High Voltage ◽  
Ideality Factor ◽  
Schottky Barrier Height ◽  
Schottky Contacts ◽  
Electrical Performance ◽  
High Temperature Annealing ◽  
Excess Current ◽  
Blocking Voltage

We investigated the effect of high temperature annealing on the Schottky barrier height (Fb) and the ideality factor (n-factor) of a Mo contact. In a Mo contact, the Fb increased and the leakage current decreased by annealing at 600oC, while no increase in n-factor and forward excess current owing to the high temperature annealing was observed. The Schottky barrier diode with Mo contact annealed at 600oC showed a blocking-voltage (Vb) of 4.15 kV and a specific on resistance (Ron) of 9.07 mWcm2, achieving a high Vb 2/Ron value of 1898 MW/cm2.

Reverse Biased Electrochemical Etching of SiC-SBD

2007 ◽  
Vol 556-557 ◽  
pp. 419-422
Author(s):  
Koichi Nishikawa ◽  
Yusuke Maeyama ◽  
Yusuke Fukuda ◽  
Masaaki Shimizu ◽  
Masashi Sato ◽  
...  
Keyword(s):  
Contact Area ◽  
Reverse Bias ◽  
Electrochemical Etching ◽  
Schottky Contact ◽  
Guard Ring ◽  
Reverse Bias Voltage ◽  
Power Devices ◽  
Substrate Reduction ◽  
Large Size ◽  
Before And After

With development of very-low-micropipe-density substrate, reduction of other device killer defects becomes important for large size power devices. We employed reverse biased electrochemical etching (RECE) method in order to elucidate where the current leaks out in Schottky barrier diode. Low concentration 4H-SiC epi-layer with Al implanted guard rings was electrochemically etched under reverse bias voltage up to 400V in HF-based electrolyte. The surface of the substrate was observed with Nomarski microscopy before and after RECE. In guard ring area, holes appeared which are aligned toward off-direction of the substrate. The length of the aligned holes is about 25μm. The guard ring surrounding the holes were etched uniformly but limited as though there exists a boundary parallel to the steps. In Schottky contact area, not all but some of carrot defects showed an etched feature after RECE. Such etching features are also observed at different position without carrot. We consider that threading screw dislocation is one cause of leakage current in SBD. An etching feature like tangled strings also appeared. Its outer dimension is more than 1mm with thickness of about 50μm. The origin of tangled-string-like feature is not clear yet.

Evolution of the Electrical Behaviour of GaN and AlGaN Materials after High Temperature Annealing and Thermal Oxidation

2010 ◽  
Vol 645-648 ◽  
pp. 1211-1214
Author(s):  
Fabrizio Roccaforte ◽  
Ferdinando Iucolano ◽  
Filippo Giannazzo ◽  
Salvatore di Franco ◽  
Corrado Bongiorno ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermal Oxidation ◽  
Surface Defects ◽  
State Density ◽  
Schottky Barriers ◽  
Electrical Activation ◽  
High Temperature Annealing ◽  
Electrical Behaviour ◽  
Dimensional Electron ◽  
Dimensional Electron Gas

In this paper, the evolution of the electrical behaviour of GaN and AlGaN materials after high-temperature annealing and thermal oxidation is discussed. In particular, annealing above 1100°C, required for electrical activation of implanted species, increases the surface state density, reducing the metal/GaN Schottky barriers and increasing the leakage current. On the other hand, the thermal oxidation at 900°C of AlGaN/GaN heterostructures showed the formation of a thin oxide layer, which can be able to passivate surface defects and/or can serve as inter-device isolation. However, a decrease of the sheet carrier density in the two dimensional electron gas (2DEG) was observed when the material is subjected to such high thermal budgets. The results are discussed considering the possible optimizations and applications to GaN-devices technology.

Microstructure studies of tungsten silicide schottky contacts on Gaas

1987 ◽  
Vol 45 ◽  
pp. 328-329
Author(s):  
Yih-Cheng Shih ◽  
E. L. Wilkie
Keyword(s):  
Thermal Stability ◽  
Field Effect Transistors ◽  
Schottky Contact ◽  
Schottky Contacts ◽  
Excellent Thermal Stability ◽  
Barrier Heights ◽  
Gaas Substrates ◽  
Film Adhesion ◽  
Threshold Voltages ◽  
Thermal Stability Of

Tungsten silicides (WSix) have been successfully used as the gate materials in self-aligned GaAs metal-semiconductor-field- effect transistors (MESFET). Thermal stability of the WSix/GaAs Schottky contact is of major concern since the n+ implanted source/drain regions must be annealed at high temperatures (∼ 800°C). WSi0.6 was considered the best composition to achieve good device performance due to its low stress and excellent thermal stability of the WSix/GaAs interface. The film adhesion and the uniformity in barrier heights and ideality factors of the WSi0.6 films have been improved by depositing a thin layer of pure W as the first layer on GaAs prior to WSi0.6 deposition. Recently WSi0.1 has been used successfully as the gate material in 1x10 μm GaAs FET's on the GaAs substrates which were sputter-cleaned prior to deposition. These GaAs FET's exhibited uniform threshold voltages across a 51 mm wafer with good film adhesion after annealing at 800°C for 10 min.

Defect reduction in oxygen implanted silicon-on-insulator material during high-temperature annealing

1989 ◽  
Vol 47 ◽  
pp. 604-605
Author(s):  
P. Roitman ◽  
B. Cordts ◽  
S. Visitserngtrakul ◽  
S.J. Krause
Keyword(s):  
High Temperature ◽  
Annealing Temperature ◽  
Silicon On Insulator ◽  
High Dose ◽  
High Temperature Annealing ◽  
High Current ◽  
Defect Reduction ◽  
Annealing Step ◽  
Multiple Cycle ◽  
Defect Densities

Synthesis of a thin, buried dielectric layer to form a silicon-on-insulator (SOI) material by high dose oxygen implantation (SIMOX – Separation by IMplanted Oxygen) is becoming an important technology due to the advent of high current (200 mA) oxygen implanters. Recently, reductions in defect densities from 109 cm−2 down to 107 cm−2 or less have been reported. They were achieved with a final high temperature annealing step (1300°C – 1400°C) in conjunction with: a) high temperature implantation or; b) channeling implantation or; c) multiple cycle implantation. However, the processes and conditions for reduction and elimination of precipitates and defects during high temperature annealing are not well understood. In this work we have studied the effect of annealing temperature on defect and precipitate reduction for SIMOX samples which were processed first with high temperature, high current implantation followed by high temperature annealing.

FERROPERM

Alloy Digest ◽  
1993 ◽  
Vol 42 (4) ◽  
Keyword(s):  
Fracture Toughness ◽  
High Temperature ◽  
Physical Properties ◽  
Saturation Magnetization ◽  
Pure Iron ◽  
Magnetic Alloy ◽  
High Saturation Magnetization ◽  
High Temperature Annealing ◽  
Soft Magnetic ◽  
Soft Magnetic Alloy

Abstract Ferroperm is a soft magnetic alloy that contains 1% aluminum. This addition of aluminum combined with high-temperature annealing increases permeability and reduces coercivity without decreasing the high-saturation magnetization of pure iron. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming. Filing Code: FE-99. Producer or source: NKK Corporation.

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