• 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.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.10
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• pp.1827-1832
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• 2017

To observe the characteristics to be a resistive memory of $V_2O_5$ deposited by oxygen various gas flows and annealed, the hysteresis curves of $V_2O_5$ were analyzed. The good resistive memory was obtained from the electrical characteristics of $V_2O_5$ films with the Schottky contact as a result of electron-hole pair, and the oxygen vacancy generated from the annealing process contributes the high quality of Schottky contact and the formation of resistive memories. The balanced Schottky contacts owing to the oxygen vacancy effect as the result of an ionic reaction were formed at the $V_2O_5$ film annealed at $150^{\circ}C$ and $200^{\circ}C$ and the balanced Schottky contact with negative to positive voltages enhanced the electrical operation with write/erase states according to the forward or reverse bias voltages for the resistive memory behavior due to the oxygen vacancy.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.133-133
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• 2008

Recently, as the down-scailing of field-effect transistor devices continues, Schottky-barrier field-effect transistors (SB-FETs) have attracted much attention as an alternative to conventional MOSFETs. SB-FETs have advantages over conventional devices, such as low parasitic source/drain resistance due to their metallic characteristics, low temperature processing for source/drain formation and physical scalability to the sub-10nm regime. The good scalability of SB-FETs is due to their metallic characteristics of source/drain, which leads to the low resistance and the atomically abrupt junctions at metal (silicide)-silicon interface. Nevertheless, some reports show that SB-FETs suffer from short channel effect (SCE) that would cause severe problems in the sub 20nm regime.[Ouyang et al. IEEE Trans. Electron Devices 53, 8, 1732 (2007)] Because source/drain barriers induce a depletion region, it is possible that the barriers are overlapped in short channel SB-FETs. In order to analyze the SCE of SB-FETs, we carried out systematic studies on the Schottky barrier overlapping in short channel SB-FETs using a SILVACO ATLAS numerical simulator. We have investigated the variation of surface channel band profiles depending on the doping, barrier height and the effective channel length using 2D simulation. Because the source/drain depletion regions start to be overlapped each other in the condition of the $L_{ch}$~80nm with $N_D{\sim}1\times10^{18}cm^{-3}$ and $\phi_{Bn}$ $\approx$ 0.6eV, the band profile varies as the decrease of effective channel length $L_{ch}$. With the $L_{ch}$~80nm as a starting point, the built-in potential of source/drain schottky contacts gradually decreases as the decrease of $L_{ch}$, then the conduction and valence band edges are consequently flattened at $L_{ch}$~5nm. These results may allow us to understand the performance related interdependent parameters in nanoscale SB-FETs such as channel length, the barrier height and channel doping.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.1
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• pp.43-47
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• 2001

Plasma polymerized hexamethyldisiloxane thin film was fabricated by employing an inter-electrode capacitively coupled type apparatus under the following conditions : carrier gas flow rate of 11 sccm, reaction pressure of 0.1 torr, discharge frequency of 13.56 MHz and discharge power of 30∼90 W. Polymerization rate of thin film fabricated at the discharge power of 90W is 32.5nm/min. Relative dielectric constant and dielectric loss tangent of thin film shows 3.2∼3.8 and 2.6x10$\^$-3/∼4.51x10$\^$-3/ respectively in the frequency range of 1 kHz∼1 MHz. As the annealing temperature is increased, the relative dielectric constant gradually decreases while the dielectric loss tangent increases. The current density increase gradually with increasing annealing temperature and electric field. The electric conduction of the heaxamethyldisiloxane thin film shows Schottky effect.

• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.2
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• pp.141-146
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• 2002

The effect of the wide-bandgap Schottky barrier enhancement cap layer on the performance of metal-semiconductor-metal photodetectors (MSMPD's) is presented. Judged by the dc characteristics, no considerable increase in recombination loss of carriers is resulted by the incorporation of the cap layer. However, about 45% of the detection efficiency is lost for the cap-layered MSMPD's even with a graded layer incorporated under pulse operation, and it was found to be due mainly to the capturing and slow release of the photocarriers at the heterointerface. The loss mechanism of the pulse detection efficiency is believed to be responsible for the intersymbol interference and the increased bit-error-rate (BER) observed in MSMPD's when used with a high bit rate pseudo-random-bit-stream (PRBS) data pattern.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.355-355
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• 2010

We studied the dependence of the performance of schottky barrier metal-oxide-field effect transistors(SB MOSFETs) on the work function of source/drain metals. A strong impact of the various work functions and the light wavelengths on the transistor characteristics is found and explained using experimental data. We used an insulator of a high thickness (100nm) and back gate issues in SOI substrate, subthreshold swing was measured to 300~400[mV/dec] comparing with a ideal subthreshold swing of 60[mV/dec]. Excellent characteristics of Al/Si was demonstrated higher on/off current ratios of ${\sim}10^7$ than others. In addition, extensive photoresponse analysis has been performed using halogen and deuterium light sources(200<$\lambda$<2000nm).

• Journal of Information Display
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• v.10 no.4
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• pp.143-148
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• 2009

The theoretical current density equations for organic semiconductors was derived according to the internal carrier emission equation based on the diffusion model at the Schottky barrier contact and the mobility equation based on the field dependence model, the so-called "Poole-Frenkel mobility model." The electric field becomes constant because of the absence of a space charge effect in the case of a higher injection barrier height and a lower sample thickness, but there is distribution in the electric field because of the space charge effect in the case of a lower injection barrier height and a higher sample thickness. The transition between the injection- and bulk-limited currents was presented according to the Schottky barrier height and the sample thickness change.

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.372-375
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• 2017

Metal-oxide-semiconductor Field-Effect transistor (MOSFET)을 대체할 기술로서 제안된 Schottky Barrier MOSFET (SB-MOSFET)가 제시되고 있다. 본 연구에서는 SB-MOSFET와 MOSFET을 다양한 소자 파라미터를 변화시킴으로서 양자역학적 전하수송 계산을 바탕으로 특성을 분석한다. MOSFET과 SB-MOSFET은 채널 두께 ($T_{Si}$)가 감소함에 따라 전류량은 증가하고 SS와 DIBL은 증가하였고 Overlap에서는 SS와 DIBL이 커지고 Underlap에서는 작아짐을 보였고 SB-MOSFET는 특히 그 폭이 컸다. 또한 SB 높이가 낮을수록 SB-MOSFET의 전류량이 증가하고 SS는 감소하였고 마찬가지로 Source와 Drain doping concentration이 낮을수록 MOSFET의 전류량은 증가하고 SS는 감소하였다. MOSFET과 SB-MOSFET의 경향은 대체로 비슷하나 변화량의 차이 등이 있었다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.4
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• pp.280-284
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• 2011

Silicon carbide (SiC)-based gas sensors can be operated at very high temperatures. So far, catalytic metal-schottky diodes respond fast to a change between a reducing and an oxidizing atmosphere. Therefore SiC diodes have been suggested for high temperature gas sensor applications. In this work, the effect of reactivity of the catalytic surface on the 4H-SiC sensor-structures in 375 K~775 K have been studied and some fundamental simulations have also been performed.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.299-304
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• 2016

2차원 반도체 소재의 경우 물질종류마다 내포하고 있는 고유결함에 의해서 Fermi-Level Pinning 이 발생하여 이로 인한 Schottky Barrier transistor로 동작을 하게 되며, 이는 접합부에 Carrier Injection 정도와 Schottky Barrier을 통과하는 Tunneling 정도에 의해서 소자의 특성이 결정 된다. 본 연구에서는 시뮬레이션을 통하여 2차원 반도체인 $MoS_2$소자를 설계하고, S/D Doping에 따라 접촉 저항 개선 효과와 소자의 동작특성이 어떠한 영향을 미치는지 연구하여 최대 $250cm^2/V{\cdot}sec$의 field effect mobility 의 결과를 얻었다. 또한 S/D doping 에 따라 각 저항 성분의 영향을 분석하였으며 면저항 및 접촉 저항 둘 다 doping 농도가 증가함에 따라 감소하는 결과를 나타내며, S/D doping의 영향은 접촉저항에서 더 크게 나타났다. 더불어 2차원 반도체의 Resistance network model 을 제안하여 subthreshold 영역에서는 $R_{ic}$, saturation 영역에서는 $R_{ish}$ 가 전체저항에서 주요한 변수로 전체저항식에 포함되어야 한다는 것을 시뮬레이션을 통해서 검증하였다.