scholarly journals Surface Modification on the Sputtering-Deposited ZnO Layer for ZnO-Based Schottky Diode

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Ren-Hao Chang ◽  
Kai-Chao Yang ◽  
Tai-Hong Chen ◽  
Li-Wen Lai ◽  
Tsung-Hsin Lee ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Schottky Diode ◽  
Ohmic Contact ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Layer Surface ◽  
Barrier Heights ◽  
Ammonium Sulfide ◽  
Current Voltage ◽  
Contact Electrode

We prepare a zinc oxide- (ZnO-) based Schottky diode constructed from the transparent cosputtered indium tin oxide- (ITO-) ZnO ohmic contact electrode and Ni/Au Schottky metal. After optimizing the ohmic contact property and removing the ion-bombardment damages using dilute HCl etching solution, the dilute hydrogen peroxide (H2O2) and ammonium sulfide (NH4)2Sxsolutions, respectively, are employed to modify the undoped ZnO layer surface. Both of the Schottky barrier heights with the ZnO layer surface treated by these two solutions, evaluated from the current-voltage (I-V) and capacitance-voltage (C-V) measurements, are remarkably enhanced as compared to the untreated ZnO-based Schottky diode. Through the X-ray photoelectron spectroscopy (XPS) and room-temperature photoluminescence (RTPL) investigations, the compensation effect as evidence of the increases in the O–H and OZnacceptor defects appearing on the ZnO layer surface after treating by the dilute H2O2solution is responsible for the improvement of the ZnO-based Schottky diode. By contrast, the enhancement on the Schottky barrier height for the ZnO layer surface treated by using dilute (NH4)2Sxsolution is attributed to both the passivation and compensation effects originating from the formation of the Zn–S chemical bond andVZnacceptors.

scholarly journals The Achievement of a Zinc Oxide-Based Homojunction Diode Using Radio Frequency Magnetron Cosputtering System

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Hung-Jen Chiu ◽  
Tai-Hong Chen ◽  
Li-Wen Lai ◽  
Ching-Ting Lee ◽  
Jhen-Dong Hong ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Radio Frequency ◽  
Ohmic Contact ◽  
Indium Tin Oxide ◽  
Reverse Current ◽  
Specific Contact Resistance ◽  
Zno Film ◽  
Current Voltage ◽  
Specific Contact ◽  
Contact Electrode

(Al + N)-codopedp-type zinc oxide (ZnO)/undopedn-type ZnO homojunction structure was deposited onto Si (100) substrate by using radio frequency (rf) magnetron cosputtering system. Transparent indium tin oxide (ITO)-ZnO cosputtered film was employed as the ohmic contact electrode to then-type ZnO film, and the specific contact resistance was optimized to2.9×10-6 Ω cm2after treating by a rapid thermal annealing (RTA) process at 400°C for 5 min under vacuum ambient. The ohmic contact behavior between the metallic Ni/Au andp-ZnO film also was improved to3.5×10-5 Ω cm2after annealing at 300°C for 3 min under nitrogen ambient. The interfacial diffusion of these ohmic contact systems which led to the optimization of the specific contact resistances by the RTA process was investigated by the Auger electron spectroscopy (AES) depth profile measurements. The diode characteristics of the resultingp-ZnO/n-ZnO homojunction structure realized with these ohmic contact electrodes were confirmed by current-voltage (I-V) measurement, which performed a forward turn-on voltage of 1.44 V with a reverse current of1.1×10-5 A at −2 V.

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.

Rectifying and Schottky characteristics of a-SixGe1−xOy with metal contacts

2014 ◽  
Vol 92 (7/8) ◽  
pp. 606-610 ◽  
Author(s):  
Md Muztoba ◽  
Mukti Rana
Keyword(s):  
Ohmic Contact ◽  
Infrared Detector ◽  
Schottky Contact ◽  
Thermionic Emission ◽  
Emission Model ◽  
Metal Contacts ◽  
Temperature Changes ◽  
Barrier Heights ◽  
Current Voltage ◽  
Semiconductor Contacts

Metal–semiconductor contacts are a vital part of semiconductor devices as they can form a Schottky barrier or an Ohmic contact. The nature of the contact plays an important role in determining the electrical and physical characteristics of the device and hence is of paramount importance in the operation of the device. In the current work we report the design, fabrication, and current–voltage (I-V) characteristics of microbolometers, a type of infrared detector where the change in temperature changes the resistance of the sensing layer. Eight different types of microbolometers were fabricated using a-SixGe1−x or a-SixGe1−xOy sensing layers and Ti, Cr, Al, Au, Ni, or Ni0.80Cr0.20 metals contacts. It has been observed that bolometers with an a-Si0.15Ge0.85 (Si was lightly p-doped) sensing layer formed a Schottky contact with Ti, Au, Cr, and Al contact metals, while bolometers with a-Si0.15Ge0.85 (Si was heavily n-doped) sensing layers formed an Ohmic contact with Au. For microbolometers with a Si0.15Ge0.85O0.039 sensing layer, both Ni and Ni0.80Cr0.20 contact metals formed the Ohmic contact. For a-SixGe1−x and a-SixGe1−xOy microbolometers, Au and Ni0.80Cr0.20 were used as the absorber layers, respectively. The I–V characteristics of the microbolometers were analyzed with a thermionic emission model. A linear dependence on the Ge composition was approximated to find the effective Richardson constant. The theory predicts Richardson constants of 112 and 50 A/cm2K2 for Si and Ge, respectively. Barrier heights of all devices are calculated and the reasons for the formation of the Ohmic and Schottky contacts are discussed.

Effect of Indentation on I-V Characteristics of Au/n-GaAs Schottky Barrier Diodes

2008 ◽  
Vol 63 (3-4) ◽  
pp. 199-202 ◽  
Author(s):  
Ahmet Faruk Ozdemir ◽  
Adnan Calik ◽  
Guven Cankaya ◽  
Osman Sahin ◽  
Nazim Ucar
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Schottky Diode ◽  
Ideality Factor ◽  
Room Temperature ◽  
Schottky Barrier Height ◽  
Vickers Microhardness ◽  
Schottky Barrier Diodes ◽  
Microhardness Test ◽  
Current Voltage

Au/n-GaAs Schottky barrier diodes (SBDs) have been fabricated. The effect of indentation on Schottky diode parameters such as Schottky barrier height (φb) and ideality factor (n) was studied by current-voltage (I-V) measurements. The method used for indentation was the Vickers microhardness test at room temperature. The experimental results showed that the I-V characteristics move to lower currents due to an increase of φb with increasing indentation weight, while contacts showed a nonideal diode behaviour.

Electrical Properties of Epitaxial Silicide-Silicon Interfaces

1985 ◽  
Vol 54 ◽  
Author(s):  
R. T. Tung ◽  
A. F. J. Levi ◽  
J. M. Gibson ◽  
K. K. Ng ◽  
A. Chantre
Keyword(s):  
Fermi Level ◽  
Single Crystal ◽  
Schottky Barrier ◽  
Surface Region ◽  
Ideal Behavior ◽  
Near Surface ◽  
Barrier Heights ◽  
Transmission Electron ◽  
Current Voltage ◽  
P Type

ABSTRACTThe Schottky barrier heights of single crystal NiSi2 layers on Si(111) have been studied by current-voltage, capacitance-voltage and activation energy techniques. Near ideal behavior is found for Schottky barriers grown on substrates cleaned at ∼820°C in ultrahigh vacuum. The Fermi level positions at the interfaces of single crystal type A and type B NiSi2 are shown to differ by ∼0.14 eV. Transmission electron microscopy demonstrated the epitaxial perfection of these suicide layers. At a cleaning temperature of 1050° C, the near surface region of lightly doped n-type Si was converted to p-type. The presence of a p-n junction was directly revealed by spreading resistance measurements and resulted in a high apparent Schottky barrier height (≥0.75 eV) which no longer bears immediate relationship to the interface Fermi level position.

Barrier Inhomogeneities of a Medium Size Mo/4H-SiC Schottky Diode

2012 ◽  
Vol 711 ◽  
pp. 188-192
Author(s):  
Muhammad Yousuf Zaman ◽  
Denis Perrone ◽  
Sergio Ferrero ◽  
Luciano Scaltrito ◽  
Marco Naretto
Keyword(s):  
Schottky Barrier ◽  
Schottky Diode ◽  
Schottky Diodes ◽  
Schottky Contact ◽  
Effective Area ◽  
Medium Size ◽  
Current Voltage ◽  
Significant Difference ◽  
Barrier Inhomogeneities ◽  
Current Voltage Characteristics

Forward current-voltage characteristics of a medium sized (3.05mm2)Mo/4H-SiC (molyb-denum on silicon carbide) Schottky diode|fabricated for high power applications | are analysedwithin a temperature range of 125-450 K. Accurate theoretical modeling is carried out using Tung'smodel in which it is considered that numerous low barrier nanometer size patches, present in uniformhigh barrier, are responsible for the inhomogeneities in the Schottky barrier of SiC-based electronicdevices. A significant difference is observed between the effective area involved in the current trans-port and the geometric area of the Schottky contact along with a dependence of the ideality factor andhe barrier height on temperature. The obtained values of uniform Schottky barrier and Richardson'sconstant are seen to be in accordance with previous works. It is concluded that the above mentionedmodel can be used to describe the electrical behaviour of Mo/4H-SiC Schottky diodes.

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