• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.3
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• pp.298-302
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• 2023

In this paper, we discussed the effect of field plate dielectric materials such as silicon dioxide (SiO₂), aluminum oxide (Al₂O₃), and hafnium oxide (HfO₂) on the breakdown characteristics of β-Ga₂O₃ Schottky barrier diodes (SBDs). The breakdown voltage (BV) of the SBDs with a field plate was higher than that of SBDs without a field plate. The higher dielectric constant of HfO₂ contributed to the superior reduction in electric field concentration at the Schottky junction edge from 5.4 to 2.4 MV/cm. The SBDs with HfO₂ field plate showed the highest BV of 720 V, and constant specific on-resistance (R_on,sp) of 5.6 mΩ·cm², resulting in the highest Baliga's figure-of-merit (BFOM) of 92.0 MW/cm². We also investigated the effect of dielectric thickness and field plate length on BV.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.30-33
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• 1999

본 연구에서는 Pt/f4-SiC Schottky barrier diodes(SBDs)의 소자 성능향상과 미세구조와의 상관관계를 규명하였다. 다른 열처리 온도구간에 따른 금속/SiC 계면의 미세구조 평가는 X-ray scattering법을 사용하여 분석하였다. 소자의 역 방향 특성은 열처리 온도가 증가함에 따라 저하되었다. As-deposited와 $850^{\circ}C$ 온도에서 열처리된 소자의 최대 항복전압은 각각 1300 V와 626 V 이었다. 그러나, 소자의 순방향 특성은 열처리 온도가 증가함에 따라 향상되었다. X-ray scattering법으로 >$650^{\circ}C$ 이상의 열처리 온도에서는 Pt/SiC 계면에서 Pt-silicides가 형성되었고, 이러한 Silicides의 형성이 Pt/SiC 계면의 평활도를 증가시킨 원인이 됨을 보였다. SBDs의 순방향 특성은 열처리 과정동안 Pt/SiC 계면에서 형성된 silicides의 결정성에 강하게 의존함을 알 수 있었다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.6
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• pp.367-371
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• 2018

1,200 V class junction barrier schottky (JBS) diodes and schottky barrier diodes (SBD) were simultaneously fabricated on the same 4H-SiC wafer. The resulting diodes were characterized at temperatures from room temperature to 473 K and subsequently compared in terms of their respective I-V characteristics. The parameters deduced from the observed I-V measurements, including ideality factor and series resistance, indicate that, as the temperature increases, the threshold voltage decreases whereas the ideality factor and barrier height increase. As JBS diodes have both Schottky and PN junction structures, the proper depletion layer thickness, $R_{on}$, and electron mobility values must be determined in order to produce diodes with an effective barrier height. The comparison results showed that the JBS diodes exhibit a larger effective barrier height compared to the SBDs.

• Korean Journal of Materials Research
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• v.19 no.1
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• pp.28-32
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• 2009

Silicon carbide (SiC) is a promising material for power device applications due to its wide band gap (3.26 eV for 4H-SiC), high critical electric field and excellent thermal conductivity. The Schottky barrier diode is the representative high-power device that is currently available commercially. A field plate edge-terminated 4H-SiC was fabricated using a lift-off process for opening the Schottky contacts. In this case, Ni/Ti dual-metal contacts were unintentionally formed at the edge of the Schottky contacts and resulted in the degradation of the electrical properties of the diodes. The breakdown voltage and Schottky barrier height (SBH, ${\Phi}_B$) was 107 V and 0.67 eV, respectively. To form homogeneous single-metal Ni/4H-SiC Schottky contacts, a deposition and etching method was employed, and the electrical properties of the diodes were improved. The modified SBDs showed enhanced electrical properties, as witnessed by a breakdown voltage of 635 V, a Schottky barrier height of ${\Phi}_B$=1.48 eV, an ideality factor of n=1.04 (close to one), a forward voltage drop of $V_F$=1.6 V, a specific on resistance of $R_{on}=2.1m{\Omega}-cm^2$ and a power loss of $P_L=79.6Wcm^{-2}$.

• Journal of IKEEE
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• v.24 no.2
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• pp.604-609
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• 2020

We investigated the influence of rapid thermal annealing on aluminum nitride (AlN) thin film Schottky barrier diodes (SBDs) manufactured structures deposited on a 4H-silicon carbide (SiC) wafer using radio frequency sputtering. The Ni/AlN/4H-SiC devices annealed at 400℃ exhibited Schottky barrier diode (SBDs) properties with an on/off current ratio that was approximately 10 times higher than that of the as-deposited device structures and the devices annealed at 600℃ as measured at room temperature. Auger electron spectroscopy (AES) measurements revealed that atomic oxygen concentrations in the annealed AlN devices at 400℃, is ascribed to the improvement in on/off ratio and the reduction of on-resistance. Additionally, we investigated the electrical characteristics of the AlN/SiC SBD structures depending on the frequency variation of sound waves.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.2
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• pp.208-214
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• 2024

This reports the electrical properties of single-crystal β-gallium oxide (β-Ga₂O₃) vertical Schottky barrier diodes (SBDs) with a different guard ring structure. The vertical Schottky barrier diodes (V-SBDs) were fabricated with two types guard ring structures, one is with metal deposited on the Al₂O₃ passivation layer (film guard ring: FGR) and the other is with vias formed in the Al₂O₃ passivation layer to allow the metal to contact the Ga₂O₃ surface (metal guard ring: MGR). The forward current values of FGR and MGR V-SBD are 955 mA and 666 mA at 9 V, respectively, and the specific on-resistance (R_on,sp) is 5.9 mΩ·cm² and 29 mΩ·cm². The series resistance (R_s) in the nonlinear section extracted using Cheung's formula was 6 Ω, 4.8 Ω for FGR V-SBD, 10.7 Ω, 6.7 Ω for MGR V-SBD, respectively, and the breakdown voltage was 528 V for FGR V-SBD and 358 V for MGR V-SBD. Degradation of electrical characteristics of the MGR V-SBD can be attributed to the increased reverse leakage current caused by the guard ring structure, and it is expected that the electrical performance can be improved by preventing premature leakage current when an appropriate reverse voltage is applied to the guard ring area. On the other hand, FGR V-SBD shows overall better electrical properties than MGR V-SBD because Al₂O₃ was widely deposited on the Ga₂O₃ surface, which prevent leakage current on the Ga₂O₃ surface.

• Journal of Power Electronics
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• v.10 no.4
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• pp.335-341
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• 2010

In this paper, an interleaved soft switching boost converter for a Photovoltaic Power Conditioning System (PV-PCS) with high efficiency is proposed. In order to raise the efficiency of the proposed converter, a 2-phase interleaved boost converter integrated with soft switching cells is used. All of the switching devices in the proposed converter achieve zero current switching (ZCS) or zero voltage switching (ZVS). Thus, the proposed circuit has a high efficiency characteristic due to low switching losses. To analyze the power losses of the proposed converter, two experimental sets have been built. One consists of normal devices (MOSFETs, Fast Recovery (FR) diodes) and the other consists of advanced power devices (CoolMOSs, SiC-Schottky Barrier Diodes (SBDs)). To verify the validity of the proposed topology, theoretical analysis and experimental results are presented.

• Journal of IKEEE
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• v.27 no.4
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• pp.556-560
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• 2023

In this study, the impact of Nitrogen implantation process on deep-level defects and lifetime in 4H-SiC Epi surfaces was comparatively analyzed. Deep Level Transient Spectroscopy (DLTS) and Time Resolved Photoluminescence (TR-PL) were employed to measure deep-level defects and carrier lifetime. As-grown Schottky Barrier Diodes (SBDs) exhibited energy levels at 0.16 eV, 0.67 eV, and 1.54 eV, while for implantation SBD, defects at 0.15 eV were observed. This indicates a reduction in defects associated with energy levels Z_1/2 and EH_6/7, known as lifetime killers, as impurities from nitrogen implantation replace titanium and carbon vacancies.