Fabrication of 1.2kV, 100A, 4H-SiC(0001) and (000-1) Junction Barrier Schottky Diodes with Almost Same Schottky Barrier Height

2010 ◽  
Vol 645-648 ◽  
pp. 893-896 ◽  
Author(s):  
Akimasa Kinoshita ◽  
Takasumi Ohyanagi ◽  
Tsutomu Yatsuo ◽  
Kenji Fukuda ◽  
Hajime Okumura ◽  
...  

It is known that a Schottky barrier height (b) of metal/C-face 4H-SiC Schottky barrier diode (SBD) differ from b of metal/Si-face 4H-SiC SBD. Furthermore, b of metal/4H-SiC SBD varies with annealing temperature. We fabricate 0.231mm2 SBD with Ti/SiC interface using Si-face and C-face 4H-SiC. These SBDs are annealed at several temperatures after a formation of the Ti/SiC interface. As a result, b of Ti/C-face 4H-SiC interface annealed at 400 oC is nearly equal to b of Ti/Si-face 4H-SiC interface annealed at 500 oC and the n-values of these SBDs are nearly equal to the ideal value (unity). Using that annealing condition, we fabricated 25mm2 junction barrier Schottky (JBS) diodes with Ti/SiC interface on Si-face and C-face 4H-SiC epitaxial substrate. b of Si-face and C-face JBS diodes are 1.26eV and 1.24eV, respectively. The leakage currents for both Si-face and C-face JBS diodes are less than 1mA/cm2. The current of 100A is obtained at the forward bias voltage of 1.95V and 2.16V for the Si-face JBS and the C-face JBS.

2019 ◽  
Vol 5 (10) ◽  
pp. eaax5733 ◽  
Author(s):  
T. Harada ◽  
S. Ito ◽  
A. Tsukazaki

High-temperature operation of semiconductor devices is widely demanded for switching/sensing purposes in automobiles, plants, and aerospace applications. As alternatives to conventional Si-based Schottky diodes usable only at 200°C or less, Schottky interfaces based on wide-bandgap semiconductors have been extensively studied to realize a large Schottky barrier height that makes high-temperature operation possible. Here, we report a unique crystalline Schottky interface composed of a wide-gap semiconductor β-Ga2O3 and a layered metal PdCoO2. At the thermally stable all-oxide interface, the polar layered structure of PdCoO2 generates electric dipoles, realizing a large Schottky barrier height of ~1.8 eV, well beyond the 0.7 eV expected from the basal Schottky-Mott relation. Because of the naturally formed homogeneous electric dipoles, this junction achieved current rectification with a large on/off ratio approaching 108 even at a high temperature of 350°C. The exceptional performance of the PdCoO2/β-Ga2O3 Schottky diodes makes power/sensing devices possible for extreme environments.


2014 ◽  
Vol 778-780 ◽  
pp. 828-831 ◽  
Author(s):  
Junichi Hasegawa ◽  
Kazuya Konishi ◽  
Yu Nakamura ◽  
Kenichi Ohtsuka ◽  
Shuhei Nakata ◽  
...  

We clarified the relationship between the enhanced leakage current of SiC Junction Barrier Schottky diodes and the stacking faults in the SiC crystal at the SiC and metal electrode interface by measuring the electrical and optical properties, and confirm by using the numerical simulations. Numerical simulation considering local lowering of Schottky barrier height, which is 0.8 eV lower than that of 4H-SiC well explained the 2-4 orders of magnitude higher reverse leakage current caused by the SFs. We concluded that the locally lowering of the Schottky barrier height at the 3C-SiC layer in the 4H-SiC surface is a main cause of the large reverse leakage current.


2014 ◽  
Vol 778-780 ◽  
pp. 710-713 ◽  
Author(s):  
Hamid Amini Moghadam ◽  
Sima Dimitrijev ◽  
Ji Sheng Han

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.


2018 ◽  
Vol 15 (11) ◽  
pp. 803-809
Author(s):  
Doldet TANTRAVIWAT ◽  
Wittawat YAMWONG ◽  
Udom TECHAKIJKAJORN ◽  
Kazuo IMAI ◽  
Burapat INCEESUNGVORN

Herein, boron implantation technique was employed to engineer the Schottky barrier height (SBH) of Ti/n-type silicon junction (Ti/n-Si). The Ti/n-Si Schottky diodes with boron doses of 4, 5.4 and 6.6´1012 cm-2 at the energy of 25 keV were fabricated with improved rectification and their effective SBHs increased from 0.49 to 0.95. The tuning of the effective SBH is mainly attributed to the presence of shallow p-layer, which modifies the energy band at Ti/n-Si interface. This work clearly shows that the ability to precisely control the SBH, regardless of the metal work function, would facilitate the implementation of Schottky diode into various semiconductor structures, such as MPS (Merged PiN Schottky) diode, in order to improve performance without major modification on the existing metal line process.


2005 ◽  
Vol 864 ◽  
Author(s):  
M. Li ◽  
W. A. Anderson

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.


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