Thermally Stable Schottky Contacts TO n-GaN

1998 ◽  
Vol 512 ◽  
Author(s):  
H. S. Venugopalan ◽  
S. E. Mohney
Keyword(s):  
Schottky Diodes ◽  
Schottky Contacts ◽  
Thermally Stable ◽  
Short Term ◽  
Barrier Heights ◽  
Current Voltage ◽  
Capacitance Voltage

ABSTRACTThe barrier heights of Ni/Ga/Ni and Re Schottky contacts to n-GaN were investigated by current-voltage (I-V) and capacitance-voltage (C-V) measurements. The elemental Ni contacts were also investigated for comparison. The Ni/Ga/Ni and Re diodes were stable on short term annealing up to 700 °C. It was also shown that the Ni/Ga/Ni (84 at% Ni, 16 at% Ga) diodes were more stable than Ni diodes. This work provides the first demonstration of Schottky diodes to n-GaN that are stable upon annealing at 700 °C.

Metallurgical and Electrical Characteristics of MoAlx Schottky Contacts to n-GaAs

1992 ◽  
Vol 260 ◽  
Author(s):  
T. S. Huang ◽  
J. G. Peng ◽  
C. C. Lin
Keyword(s):  
Thermal Processing ◽  
Annealing Temperature ◽  
Schottky Diodes ◽  
Schottky Contacts ◽  
Electrical Characteristics ◽  
Interfacial Stability ◽  
X Ray Diffraction ◽  
X Ray ◽  
Barrier Heights ◽  
Current Voltage

ABSTRACTThe interfacial stability, surface morphology and electrical characteristics of MoAlx contacts to n-GaAs have been investigated by using x-ray diffraction, scanning electron microscopy, sheet resistance and current-voltage measurements. The compositions of rf-cosputtered MoAlx films were x = 0.35, 2.7, and 7.0, respectively. The contacts were annealed by rapid thermal processing in the temperature range 500–1000 °C for 20 s. The interfaces of MoAl0.35/GaAs and MoAl2,7/GaAs were stable up to 900 °C, while the interfaces of MoAl7.0/GaAs were less stable and reactions occurred above 800 °C. The variations of sheet resistances and the barrier heights of the Schottky diodes as a function of annealing temperatures can be well correlated to the interfacial stability. The MoAl2.7/n-GaAs diodes exhibited the best stability and were characterized by the highest barrier height (0.98 V) and nearly unit ideality factor (1.11) after annealing at 900 °C. For all thermally stable MoAlx/n-GaAs Schottky diodes, the barrier heights increased with annealing temperature.

scholarly journals Electrical Properties of Rapidly Annealed Ir and Ir/Au Schottky Contacts on n-Type InGaN

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
V. Rajagopal Reddy ◽  
B. Prasanna Lakshmi ◽  
R. Padma
Keyword(s):  
Barrier Height ◽  
Annealing Temperature ◽  
Schottky Diodes ◽  
Forward Bias ◽  
Interface State ◽  
Schottky Contacts ◽  
Barrier Heights ◽  
Current Voltage ◽  
State Densities ◽  
Optimum Annealing Temperature

The effect of annealing temperature on electrical characteristics of iridium (Ir) and iridium/gold (Ir/Au) Schottky contacts to n-type InGaN have been investigated by means of current-voltage (I-V) and capacitance-voltage (C-V) techniques. It is observed that the barrier height of Ir/n-InGaN and Au/Ir/n-InGaN Schottky diodes increases after annealing at 300∘C for 1 min in N2 ambient compared to the as-deposited. However, the barrier heights are found to be decreased somewhat after annealing at 500∘C for the both Ir and Ir/Au Schottky contacts. From the above observations, it is clear that the optimum annealing temperature for both Ir and Ir/Au Schottky contacts is 300∘C. Moreover, the barrier height (ϕb), ideality factor (n) and series resistance (RS) are determined using Cheung’s and Norde methods. Besides, the energy distribution of interface state densities are determined from the forward bias I-V characteristics by taking into account the bias dependence of the effective barrier height. Based on the above results, it is clear that both Ir and Ir/Au Schottky contacts exhibit a kind of thermal stability during annealing.

Schottky Contacts to N-Type 4H-SiC Fabricated with Ti-, Mo-, Ni- and Al-Based Metallizations

2011 ◽  
Vol 679-680 ◽  
pp. 453-456
Author(s):  
Denis Perrone ◽  
Sergio Ferrero ◽  
Luciano Scaltrito ◽  
Marco Naretto ◽  
Edvige Celasco ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Schottky Diodes ◽  
Schottky Contact ◽  
Structural Evolution ◽  
Schottky Contacts ◽  
Power Losses ◽  
X Ray ◽  
Current Voltage ◽  
Capacitance Voltage ◽  
Power Densities

In this work we studied different Schottky contacts to 4H-SiC with the aim to obtain Schottky Barrier diodes (SBDs) and Junction Barrier Schottky diodes (JBS) able to operate at high temperatures, frequencies and power densities with low power losses. Schottky contacts were fabricated using Mo and Mo/Al layers annealed up to 600 °C using a Rapid Thermal Process (RTP). A comparison with previous results obtained with Ni, Ti and Ti/Al layers annealed up to 400 °C is also proposed. The Schottky contacts were characterized by means of standard Current-Voltage (I-V) and Capacitance-Voltage (C-V) techniques. X-ray Photoelectron Spectroscopy (XPS) analyses were performed in depth profile mode in order to study the structural evolution of the interface Mo/SiC and Al/Mo during annealing treatments. Mo/Al contacts show a lower barrier height and better overall performances in forward polarization when compared to the Ti- and Ni-based contacts, and they are very promising for Schottky contact fabrication on SBD and JBS.

Contact Characterizations of ZrN Thin Films Obtained by Reactive Sputtering

2007 ◽  
Vol 1040 ◽  
Author(s):  
Joshua Pelleg ◽  
Asaf Bibi ◽  
Michael Sinder
Keyword(s):  
Thin Films ◽  
Schottky Diodes ◽  
Reactive Sputtering ◽  
Barrier Heights ◽  
Current Voltage ◽  
Capacitance Voltage ◽  
P Type

AbstractThe contact properties of ZrN on p-type Si obtained by magnetron reactive sputtering were investigated. Schottky diodes characteristics were evaluated by current-voltage (I-V) and capacitance voltage (C-V) measurements. The barrier heights obtained by I-V and C-V are in the range of 0.55-0.63V and 0.88-0.91V, respectively.

Metal Contacts on a-GaN

1996 ◽  
Vol 1 ◽  
Author(s):  
T. U. Kampen ◽  
W. Mönch
Keyword(s):  
Tight Binding ◽  
Image Force ◽  
Schottky Contacts ◽  
Metal Contacts ◽  
Zero Bias ◽  
Barrier Heights ◽  
Current Voltage ◽  
Optical Dielectric Constant ◽  
Optical Dielectric ◽  
Gap States

The Schottky barrier heights of silver and lead contacts on n-type GaN (0001) epilayers were determined from current-voltage characteristics. The zero-bias barrier heights and the ideality factors were found to be linearly correlated. Similar observations were previously reported for metal contacts on Si (111) and GaAs (110) surfaces. The barrier heights of ideal Schottky contacts are characterized by image force lowering of the barrier only. This gives an ideality factor of 1.01. From our data we obtain barrier heights of 0.82 eV and 0.73eV for ideal Ag and Pb contacts on GaN, respectively. The metal-induced gap states (MIGS) model predicts the barrier heights of ideal Schottky contacts on a given semiconductor to be linearly correlated with the electronegativities of the metals. The two important parameters of this MIGS-and-electronegativity model are the charge neutrality level (CNL) of the MIGS and a slope parameter. The CNL may be calculated from the dielectric band gap and using the empirical tight-binding method. The slope parameters are given by the optical dielectric constant of the respective semiconductor. The predictions of the MIGS model for metal/GaN contacts are confirmed by the results presented here and by barrier heights previously reported by others for Au, Ti, Pt, and Pd contacts on GaN.

High Barrier Height n-GaN Schottky diodes with a barrier height of 1.3 eV by using sputtered copper metal

1999 ◽  
Vol 572 ◽  
Author(s):  
W. C. Lai ◽  
M. Yokoyama ◽  
C. Y. Chang ◽  
J. D. Guo ◽  
J. S. Tsang ◽  
...  
Keyword(s):  
Barrier Height ◽  
Vapor Deposition ◽  
Schottky Diodes ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Copper Metal ◽  
Current Voltage ◽  
Capacitance Voltage ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

ABSTRACTCopper Schottky diodes on n-type GaN grown by metal-organic chemical vapor deposition were achieved and investigated. Ti/Al was used as the ohmic contact. The copper metal is deposited by the Sputter system. The barrier height was determined to be as high as (ΦB =1.13eV by current-voltage (I-V) method and corrected to be ΦB =1.35eV as considered the ideality factor, n, with the value of 1.2. By the capacitance-voltage (C-V) method, the barrier height is determined to be ΦB =1.41eV. Both results indicate that the sputtered copper metal is a high barrier height Schottky metal for n-type GaN.

EFFECT OF SURFACE PASSIVATION ON CAPACITANCE–VOLTAGE CHARACTERISTICS OF Sn/p-Si SCHOTTKY CONTACTS

2011 ◽  
Vol 25 (04) ◽  
pp. 531-542
Author(s):  
CABİR TEMİRCİ ◽  
BAHRI BATI
Keyword(s):  
Chemical Treatment ◽  
Room Temperature ◽  
Surface Passivation ◽  
Anodic Oxide ◽  
Treatment Method ◽  
Schottky Contacts ◽  
Metal Insulator ◽  
Current Voltage ◽  
Capacitance Voltage ◽  
Effect Of Surface

We have fabricated the Sn/p-Si Schottky barrier diodes with the interfacial layer metal–insulator–semiconductor (D-MIS) and the surface passivation metal–semiconductor MS (D-MS) by the anodization or chemical treatment method. The current–voltage (I–V) and capacitance–voltage (C–V) characteristics of the devices were measured at room temperature. We obtained that the excess capacitance (C0) value of the MIS Sn/p-Si diode with the anodic oxide layer of 16.88 pF and 0.12 pF for the MS Sn/p-Si ideal diode with the surface passivation by the anodization or chemical treatment method from reverse bias C–V characteristics. Thus, we have succeeded to diminish the excess capacitance value to the limit of 0.12 pF for the MS Sn/p-Si diode by using the anodization or chemical treatment method.

Comparison of Microwave ECR and RF Plasmas for Dry Etching of Single Crystal 6H-SiC

1994 ◽  
Vol 339 ◽  
Author(s):  
J. R. Flemish ◽  
K. Xie ◽  
W. Buchwald ◽  
L. Casas ◽  
J. H. Zhao ◽  
...  
Keyword(s):  
Single Crystal ◽  
Plasma Etching ◽  
Electron Cyclotron Resonance ◽  
Schottky Diodes ◽  
Substrate Bias ◽  
Rf Plasmas ◽  
Ecr Plasma ◽  
Current Voltage ◽  
Capacitance Voltage ◽  
Etch Rates

ABSTRACTElectron cyclotron resonance (ECR) plasma etching of single crystal 6H-SiC has been investigated using a CF4/O2 gas mixture and compared to conventional reactive ion etching (RIE) in a radio frequency (13.56 MHz) reactor. The use of ECR results in higher etch rates, lower levels of bias and smoother etched surfaces than rf-RIE. ECR etch rates exceeding 100 nm/min have been obtained at a substrate bias of-100 V. Etch rate and surface morphology have been studied as a function of pressure, bias and power. Auger electron spectroscopy shows that ECR etching leaves no residues unlike rf-RIE which leaves residues containing Al, F, O and C. The current-voltage and capacitance-voltage measurements of Schottky diodes show that there is far less damage induced by ECR etching compared to rf-RIE.

Impact of Interface Traps on Current-Voltage Characteristics of 4H-SiC Schottky-Barrier Diodes

2014 ◽  
Vol 778-780 ◽  
pp. 710-713 ◽  
Author(s):  
Hamid Amini Moghadam ◽  
Sima Dimitrijev ◽  
Ji Sheng Han
Keyword(s):  
Schottky Barrier ◽  
Schottky Barrier Height ◽  
Schottky Diodes ◽  
Forward Bias ◽  
Interface Traps ◽  
Barrier Heights ◽  
Current Voltage ◽  
Donor Type ◽  
Current Voltage Characteristics ◽  
Expected Values

This paper presents a physical model based on interface traps to explain both the larger barrier heights of practical Schottky diodes in comparison to the theoretically expected values and the appearance of a knee in the log I–V characteristics. According to this model, acceptor-type interface traps near the valance band increase the Schottky barrier height, which shifts the log I–V characteristic to higher forward-bias voltages. In addition to the acceptor traps, donor-type interface traps can appear near the conduction band, and when they do, they cause the knee in the log I–V characteristics as their energy level falls below the Fermi level and the charge associated with these traps changes from positive to neutral.

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