Observation of Defects that Reduce Schottky Barrier Height in 4H-SiC Schottky Contacts Using Electrochemical Deposition of ZnO

2011 ◽  
Vol 50 ◽  
pp. 036603 ◽  
Author(s):  
Masashi Kato ◽  
Hidenori Ono ◽  
Masaya Ichimura ◽  
Gan Feng ◽  
Tsunenobu Kimoto
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Electrochemical Deposition ◽  
Schottky Barrier Height ◽  
Schottky Contacts

Defect Reduction in Si-based Metal-Semiconductor-Metal Photodetectors with Cryogenic Processed Schottky Contacts

2005 ◽  
Vol 864 ◽  
Author(s):  
M. Li ◽  
W. A. Anderson
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Dark Current ◽  
Schottky Barrier Height ◽  
Schottky Diodes ◽  
Schottky Contacts ◽  
Metal Deposition ◽  
Active Area ◽  
Electrode Spacing ◽  
Metal Semiconductor Metal

AbstractMetal-Semiconductor-Metal photodetectors (MSM-PD's) and simple Schottky diodes were fabricated using a low temperature (LT) technique to greatly reduce the device dark current. LT processing for metal deposition increased Schottky barrier height by improving the interface between metal and semiconductor to reduce the leakage current of the device. The structure consists of a 20 Å oxide over the active area to passivate surface states, a thicker oxide under contact pads to reduce dark current and the interdigitated Schottky contacts. A comparison was made for Schottky metal deposited with the substrate at 25 °C or -50 °C (LT). The devices fabricated using the LT process had better I-V characteristics compared to detectors fabricated using the standard room temperature (RT) metal deposition technique. The dark current for the LT film was found to be one to three orders lower in magnitude compared to the film deposited at RT. In one case, for example, the dark current was significantly reduced from 1.69 nA to 4.58 pA at 1.0 V. The active area for the device was determined to be 36 × 50 μm2 with 4 μm electrode width and 4 μm electrode spacing. Additionally, LT-MSM-PD's exhibited an excellent linear relationship between the photo-current and the incident light power. The Schottky barrier height for LT processing was found to be 0.79 eV; however, this value was 0.1 eV more than that of the same contact obtained by RT processing.

Delineation of Defects Reducing Schottky Barrier Heights on 4H-SiC by the Electrochemical Deposition

2008 ◽  
Vol 600-603 ◽  
pp. 373-376
Author(s):  
Masashi Kato ◽  
Kazuya Ogawa ◽  
Masaya Ichimura
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Electrochemical Deposition ◽  
Schottky Barrier Height ◽  
Proper Time ◽  
Etch Pits ◽  
Barrier Heights ◽  
Etch Pit ◽  
Deposition Voltage ◽  
Deposited Films

We identified regions with low Schottky barrier height on 4H-SiC surfaces by the electrochemical deposition of ZnO. When we adopt an appropriate deposition voltage, ZnO grew preferentially at the regions with the low Schottky barrier height. Thus, we were able to identify the ZnO film only at these regions if we stopped the deposition at a proper time. We compared positions of the deposited film and etch pit after molten NaOH etching. As a result, in a bulk 4H-SiC, the films were deposited around some of micropipe positions. On the other hand, in an epitaxial 4H-SiC layer, although approximately a half of deposited films seemed to grow at the etch-pit defect positions, other deposited films were grown at positions without etch-pit defects. Therefore the Schottky barrier heights were reduced by not only defects emerging as etch pits but also other kind of origins in epitaxial 4H-SiC.

Lognormal Lateral Distribution of Barrier Height in Au/n-GaAs Schottky Junctions?

1992 ◽  
Vol 260 ◽  
Author(s):  
ZS. J. Horváth
Keyword(s):  
Normal Distribution ◽  
Schottky Barrier ◽  
Barrier Height ◽  
Schottky Barrier Height ◽  
Schottky Contacts ◽  
Point Of View ◽  
Lateral Distribution ◽  
Physical Point ◽  
Capacitance Voltage ◽  
Schottky Junctions

ABSTRACTExperimental capacitance-voltage (C-V) characteristics are presented for Au/n-GaAs Schottky contacts. The deviation of the obtained C-V characteristics from the theoretical one including the linear regions of the 1/Ca-V plot may be explained by either the normal or the lognormal lateral distribution of the barrier height. It is concluded that from physical point of view the lognormal lateral distribution of the Schottky barrier height proposed first in this work, is more likely than the normal distribution.

Correlation between Schottky Contact Characteristics and Regions with a Low Barrier Height Revealed by the Electrochemical Deposition on 4H-SiC

2010 ◽  
Vol 645-648 ◽  
pp. 669-672 ◽  
Author(s):  
Masashi Kato ◽  
H. Ono ◽  
Masaya Ichimura
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Electrochemical Deposition ◽  
Schottky Barrier Height ◽  
Schottky Diodes ◽  
Schottky Contact

We performed electrochemical deposition of ZnO on the surfaces of 4H-SiC epilayers and characterized Ni Schottky diodes fabricated on the same epilayers. We found correlation between positions where ZnO was deposited and positions where Schottky barrier height of Ni contacts is lower than of the rest of the contacts. Parts of the surface where ZnO was deposited were observed by AFM after removal of the ZnO layer, and we discussed the origin of the low Schottky barrier height from the AFM images.

Thermal Annealing Effects Study on Electrical and Structural Properties for Ni-Au/n-GaN Schottky Contacts

2013 ◽  
Vol 284-287 ◽  
pp. 241-244 ◽  
Author(s):  
Chi Yu Wang ◽  
Hung Pin Shiao ◽  
Po Wei Shieh ◽  
Hsin Hua Chang
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Thermal Annealing ◽  
Schottky Barrier Height ◽  
Annealing Process ◽  
Schottky Contacts ◽  
Interfacial Structure ◽  
Annealing Effects ◽  
Thermal Annealing Process ◽  
Ultraviolet Photodetectors

Abstract. The effects of thermal annealing on the electrical and interfacial structure properties of Ni/Au on n-type GaN Schottky contacts were investigated by current-voltage (I-V) . Based on the I-V measurement study, it was found that the Schottky barrier height increased when the contact was annealed in the 300 °C – 400 °C temperature range. A drastic improvement of the Schottky barrier height was attained by thermal annealing at 400 °C for 10 minutes. However, it degraded when the annealing temperature exceeded 500 °C. The contact annealed at 550 °C showed nonrectifying behavior. For this paper, the GaN metal-semiconductor-metal (MSM) ultraviolet photodetectors were fabricated using Ni/Au Schottky contacts. As expected, compared with the MSM detector without the thermal annealing process, the dark current of the MSM device with the 400 °C thermal annealing process drastically decreased as much as three orders of magnitude, due to the enhancement of the Schottky barrier height

scholarly journals Enhancement of the Schottky Barrier Height using a Nitrogen-Rich Tungsten Nitride Thin Film for the Schottky Contacts on AlGaN/GaN Heterostructures

2008 ◽  
Vol 37 (5) ◽  
pp. 624-627 ◽  
Author(s):  
Chung-Yu Lu ◽  
Edward Yi Chang ◽  
Jui-Chien Huang ◽  
Chia-Ta Chang ◽  
Mei-Hsuan Lin ◽  
...  
Keyword(s):  
Thin Film ◽  
Schottky Barrier ◽  
Barrier Height ◽  
Schottky Barrier Height ◽  
Schottky Contacts ◽  
Tungsten Nitride
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