• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.4
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• pp.218-221
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• 2015

Power MOSFETs (metal oxide semiconductor field effect transistor) operate as energy control semiconductor switches. In order to reduce energy loss of the device during switch-on state, it is essential to increase its conductance. In this study we have investigated a structure to reduce the on-resistance characteristics of the MOSFET. We have a proposed MOSFET structure of active cells region buried under the gate pad. The measurement are carried out with a EDS to analyze electrical characteristics, and the proposed MOSFET are compared with the conventional MOSFET. The result of proposed MOSFET was 1.68[${\Omega}$], showing 10% improvement compared to the conventional MOSFET at 700[V].

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1463-1465
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• 1994

The electrical characteristics of $Al/Ta_2O_5/Si$ metal-oxide-semiconductor (MOS) capacitors were studied. $Ta_2O_5$ films on p-type silicon had been prepared by ionized cluster beam epitaxy technique (ICBE). This $Ta_2O_5$ films have low leakage current, high breakdown strength and low flat band shift. In this research, a single crystalline cpitaxial film of $Ta_2O_5$ has been grown on p-Si wafer using an ICBE technique. The native oxide layer ($SiO_2$) on the silicon substrate was removed below $500^{\circ}C$ by use of an accelerated arsenic ion beam, instead of a high temperature deposition. $Ta_2O_5$ films formed by ICBE technique can be received considerable attention for applications to coupling capacitors, gate dielectrics in MOS devices, and memory storage capacitor insulator because of their high dielectric constants above 20 and low temperature process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.12
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• pp.1122-1127
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• 1998

Group II-AF_2$films such as $CaF_2$, $SrF_2$, and $BaF_2$ have been commonly used many practical applications such as silicon on insulatro(SOI), three-dimensional integrated circuits, buffer layers, and gate dielectrics in filed effect transistor. This paper presents electrical and structural properties of fluoride films as a gate dielectric layer. Conventional gate dielectric materials of TFTs like oxide group exhibited problems on high interface trap charge density($D_it$), and interface state incorporation with O-H bond created by mobile hydrogen and oxygen atoms. To overcome such problems in conventional gate insulators, we have investigated $CaF_2$ films on Si substrates. Fluoride films were deposited using a high vacuum evaporation method on the Si and glass substrate. $CaF_2$ films were preferentially grown in (200) plane direction at room temperature. We were able to achieve a minimum lattice mismatch of 0.74% between Si and $CaF_2$ films. Average roughness of $CaF_2$ films was decreased from 54.1 ${\AA}$ to 8.40 ${\AA}$ as temperature increased form RT and $300^{\circ}C$. Well fabricated MIM device showed breakdown electric field of 1.27 MV/cm and low leakage current of $10^{-10}$ A/$cm^2$. Interface trap charge density between $CaF_2$ film and Si substrate was as low as $1.8{\times}10^{11}cm^{-2}eV^{-1}$.

• Transactions on Electrical and Electronic Materials
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• v.2 no.1
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• pp.32-38
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• 2001

A new small sized Lateral Trench electrode Insulated Gate Bipolar Transistor(LTEIGBT) was proposed to improve the characteristics of conventional Lateral IGBT (LIGBT) and Lateral Trench gate IGBT (LTIGBT). The entire electrode of LTEIGBT was replace with trench-type electrode. The LTEIGBT was designed so that the width of device was no more than 19 ㎛. The Latch-up current densities of LIGBT, LTIGBT and the proposed LTEIGBT were 120A/㎠, 540A/㎠, and 1230A/㎠, respectively. The enhanced latch-up capability of the LTEIGBT was obtained through holes in the current directly reaching the cathode via the p+ cathode layer underneath n+ cathode layer. The forward blocking voltage of the LTEIGBT is 130V. Conventional LIGBT and LTIGBT of the same size were no more than 60V and 100V, respectively. Because the the proposed device was constructed of trench-type electrodes, the electric field moved toward trench-oxide layer, and punch through breakdown of LTEIGBT is occurred, lately.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.338-341
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• 2002

A new small size Lateral Trench Electrode Insulated Gate Bipolar Transistor (LTEIGBT) is proposed and fabricated to improve the characteristics of device. The entire electrode of LTEIGBT is placed to trench type electrode. The LTEIGBT is designed so that the width of device is 19$\mu\textrm{m}$. The latch-up current density of the proposed LTEIGBT is improved by 10 and 2 times with those of the conventional LIGET and LTIGBT The forward blocking voltage of the LTEIGBT is 130V. At the same size, those of conventional LIGBT and LTIGBT are 60V and 100V, respectively. Because that the electrodes of the proposed device is formed of trench type, the electric field in the device are crowded to trench oxide. We fabricated He proposed LTEIGBT after the device and process simulation was finished. When the gate voltage is applied 12V, the forward conduction currents of the proposed LTEIGBT and the conventional LIGBT are 80mA and 70mA, respectively, at the same breakdown voltage of 150V,

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.2
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• pp.109-113
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• 2020

A power device is a component used as a switch or rectifier in power electronics to control high voltages. Consequently, power devices are used to improve the efficiency of electric-vehicle (EV) chargers, new energy generators, welders, and switched-mode power supplies (SMPS). Power device designs, which require high voltage, high efficiency, and high reliability, are typically based on MOSFET (metal-oxide-semiconductor field-effect transistor) and IGBT (insulated-gate bipolar transistor) structures. As a unipolar device, a MOSFET has the advantage of relatively fast switching and low tail current at turn-off compared to IGBT-based devices, which are built on bipolar structures. A superjunction structure adds a p-base region to allow a higher yield voltage due to lower R_DS (on) and field dispersion than previous p-base components, significantly reducing the total gate charge. To verify the basic characteristics of the superjunction, we worked with a planar type MOSFET and Synopsys' process simulation T-CAD tool. A basic structure of the superjunction MOSFET was produced and its changing electrical characteristics, tested under a number of environmental variables, were analyzed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.9
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• pp.758-763
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• 2002

A new small size Lateral Trench Electrode Insulated Gate Bipolar Transistor (LTEIGBT) is proposed and fabricated to improve the characteristics of device. The entire electrode of LTEIGBT is placed to trench type electrode. The LTEIGBT is designed so that the width of device is 19w. The latch-up current density of the proposed LTEIGBT is improved by 10 and 2 times with those of the conventional LIGBT and LTIGBT. The forward blocking voltage of the LTEIGBT is 130V. At the same size, those of conventional LIGBT and TIGBT are 60V and 100V, respectively. Because the electrodes of the proposed device is formed of trench type, the electric field in the device are crowded to trench oxide. When the gate voltage is applied 12V, the forward conduction currents of the proposed LTEIGBT and the conventional LIGBT are 80mA and 70mA, respectively, at the same breakdown voltage of 150V.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.5
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• pp.270-277
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• 2000

A new Lateral Trench-MOS Bipolar-Mode Field-Effect Transistor(LTMBMFET) is proposed and verified by MEDICI simulation. By using a trench MOS structure, the proposed device can enhance the current gain without sacrificing other device characteristics such as the breakdown voltage. The channel region of the proposed device is formed between the trench MOS structure. So the effect of the substrate voltage is negligible when compared with the conventional device which has a channel region between the gate junction and the buried oxide layer.

• 한국컴퓨터산업교육학회:학술대회논문집
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• 2003.11a
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• pp.71-74
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• 2003

A vertical trench electrode type EST has been proposed in this paper. The proposed device considerably improve the snap-back effect which leads to a lot of problem of device applications. In this paper, the vertical dual gate Emitter Switched Thyristor(EST) with trench electrode has been proposed for improving snap-back effect. It is observed that the forward blocking voltage of the proposed device is 800V. The conventional EST of the same size were no more than 633V. Because the proposed device was constructed of trench-type electrode, the electric field moved toward trench-oxide layer, and the punch through breakdown of the proposed EST is occurred at latest.

• Transactions on Electrical and Electronic Materials
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• v.2 no.3
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• pp.33-37
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• 2001

A vertical trench electrode type EST has been proposed in this paper. The proposed device considerably improves snapback which leads to a lot of problems of device applications. In this paper, the vertical dual gate Emitter Switched Thyristor (EST) with trench electrode has been proposed for improving snab-back effect. It is observed that the forward blocking voltage of the proposed device is 745V. The conventional EST of the same size were no more than 633V. Because the proposed device was constructed of trench-type electrodes, the electric field moved toward trench-oxide layer, and the punch through breakdown of the proposed EST is occurred at latest.