• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1038-1041
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• 2002

In this paper, we have proposed a novel trench electrode Base Resistance Thyristor(BRT) and trench electrode BRT with a intrinsic region. A new power BRTs have shown superior electrical characteristics including snab-back effect and forward blocking voltage more than the conventional BRT Especially, the trench electrode BRT with intrinsic region has obtained high blocking voltage of 1600V. The blocking voltage of conventional BRT is about 400V at the same size. Because the breakdown mechanism of BRT is avalanch breakdown by impact ionization, the trench electrode BRT with intrinsic region has suppressed impact ionization, effectively. If we use this principle, we can develope super high voltage power device and applicate to another power device including IGBT, EST and etc,

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.292-295
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• 2004

The SIT was introduced by Nishizawa. in 1972. When compared with high-voltage, power bipolar junction transistors, SITs have several advantages as power switching devices. They have a higher input impedance than do bipolar transistors and a negative temperature coefficient for the drain current that prevents thermal runaway, thus allowing the coupling of many devices in parallel to increase the current handling capability. Furthermore, the SIT is majority carrier device with a higher inherent switching speed because of the absence of minority carrier recombination, which limits the speed of bipolar transistors. This also eliminates the stringent lifetime control requirements that are essential during the fabrication of high-speed bipolar transistors. This results in a much larger safe operating area(SOA) in comparison to bipolar transistors. In this paper, vertical SIT structures are proposed to improve their electrical characteristics including the blocking voltage. Besides, the two dimensional numerical simulations were carried out using ISE-TCAD to verify the validity of the device and examine the electrical characteristics. A trench gate region oxide power SIT device is proposed to improve forward blocking characteristics. The proposed devices have superior electrical characteristics when compared to conventional device. Consequently, the fabrication of trench oxide power SIT with superior stability and electrical characteristics is simplified.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.312-315
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• 2003

Basic design of RC-GCTs (Reserve-Conducting Gate-Commutated Thyristors) by novel punch-through (PT) concept with 5,500v rated voltage is described here. A PT and NPT (non punch-through) concept for the same blocking voltage has been compared in detail. The simulation work indicates that GCT with such PT design exhibits that the forward breakdown voltage is 6,400V which is enough for supporting 5500V blocking. Additionally, the real IGCT turn-off in the mode of PNP transistor has been realized. However, the carrier extraction from N-base to gate terminal will be drastic slowly in terms of NPT structure except for the high on-state voltage drop.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.7
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• pp.546-550
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• 2001

A new Lateral Trench Insulated Gate Bipolar Transistor(LTIGBT) with p$^{+}$ diverter was proposed to improve the characteristics of the conventional LTIGBT. The forward blocking voltage of the proposed LTIGBT with p$^{+}$ diverter was about 140V. That of the conventional LTIGBT of the same size was 105V. Because the p$^{+}$ diverter region of the proposed device was enclosed trench oxide layer, he electric field moved toward trench-oxide layer, and punch through breakdown of LTIGBT with p$^{+}$ diverter was occurred, lately. Therefore, the p$^{+}$ diverter of the proposed LTIGBT didn't relate to breakdown voltage in a different way the conventional LTIGBT. The Latch-up current densities of the conventional LTIGBT and proposed LTIGBT were 540A/$\textrm{cm}^2$, and 1453A/$\textrm{cm}^2$, respectively. The enhanced latch-up capability of the proposed LTIGBT was obtained through holes in the current directly reaching the cathode via the p$^{+}$ divert region and p$^{+}$ cathode layer beneath n$^{+}$ cathode layer./ cathode layer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.392-395
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• 2003

For the first time, the new dual trench gate Emitter Switched Thyristor is proposed for eliminating snap-back effect which leads to a lot of serious problems of device applications. Also, the parasitic thyristor that is inherent in the conventional EST is completely eliminated in the proposed EST structure, allowing higher maximum controllable current densities for ESTs. Moreover, the new dual trench gate allows homogenous current distribution throughout device and preserves the unique feature of the gate controlled current saturation of the thyristor current. The conventional EST exhibits snap-back with the anode voltage and current density 2.73V and $354/{\S}^2$, respectively. But the proposed EST exhibits snap-back with the anode voltage and current density 0.93V and $58A/{\S}^2$, respectively. Saturation current density of the proposed EST at anode voltage 6.11V is $3797A/{\S}^2$. The characteristics of 700V forward blocking of the proposed EST obtained from two dimensional numerical simulations (MEDICI) is described and compared with that of the conventional EST.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.267-270
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• 2001

A new small scaling Lateral Trench Insulated Gate Bipolar Transistor (SSLTIGBT) was proposed to improve the characteristics of the device. The entire electrode of the LTIGBT was replaced with a trench-type electrode. The LTIGBT was designed so that the width of device was no more than 10$\mu\textrm{m}$. The latch-up current densities were improved by 4.5 and 7.6 times, respectively, compared to those of the same sifted conventional LTIGBT and the conventional LTIGBT which has the width of 17$\mu\textrm{m}$. The enhanced latch-up capability of the SSLTIGBT was obtained due to the fact that the hole current in the device reaches the cathode via the p+ cathode layer underneath the n+ cathode layer, directly. The forward blocking voltage of the SSLTIGBT was 125 V. At the same size, those of the conventional LTIGBT and the conventional LTIGBT with the width of 17$\mu\textrm{m}$ were 65 V and 105 V, respectively. Because the proposed device was constructed of trench-type electrodes, the electric field in the device were crowded to trench oxide. Thus, the punch through breakdown of LTEIGBT occurred late.

• Transactions on Electrical and Electronic Materials
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• v.2 no.4
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• pp.15-18
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• 2001

A new small scaling Lateral Trench Insulated Gate Bipolar Transistor (SSLTIGBT) was proposed to improve the characteristics of the device. The entire electrode of the LTIGBT was replaced with a trench-type electrode. The LTIGBT was designed so that the width of device was no more than 10 ${\mu}{\textrm}{m}$. The latch-up current densities were improved by 4.5 and 7.6 times, respectively, compared to those of the same sized conventional LTIGBT arid the conventional LTIGBT which has the width of 17 ${\mu}{\textrm}{m}$. The enhanced latch-up capability of the SSLTIGBT was obtained due to the fact that the hole current in the device reaches the cathode via the p+ cathode layer underneath the n+ cathode layer, directly. The forward blocking voltage of the SSLTIGBT was 125 V. At the same size, those of the conventional LTIGBT and the conventional LTIGBT with the width of 17 ${\mu}{\textrm}{m}$ were 65 V and 105 V, respectively. Because the proposed device was constructed of trench-type electrodes, the electric field In the device were crowded to trench oxide. Thus, the punch through breakdown of LTEIGBT occurred late.

• Journal of IKEEE
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• v.17 no.4
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• pp.428-433
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• 2013

In this study, an 4H-SiC Trench MOS Barrier Schottky (TMBS) rectifier which utilizes the trapezoid mesa structure and the upper half of the trench sidewall is proposed to improve the forward voltage drop and reverse blocking voltage concurrently. The proposed 4H-SiC TMBS rectifier reduces the forward voltage drop by 12% compared to the conventional 4H-SiC TMBS rectifier with the tilted sidewall and improves the reverse blocking voltage by 11% with adjusting the length of the upper sidewall. The Silvaco T-CAD was used to analyze the electrical characteristics.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.10
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• pp.912-917
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• 2006

In this paper, Trench emitter electrode IGBT structure is proposed and studied numerically using the device simulator, MEDICI. The breakdown voltage, on-state voltage drop, latch up current density and turn-off time of the proposed structure are compared with those of the conventional trench gate IGBT(TIGBT) structures. Enhancement of the breakdown voltage by 19 % is obtained in the proposed structure due to dispersion of electric field at the edge of the bottom trench gate by trench emitter electrode. In addition, the on-state voltage drop and the latch up current density are improved by 25 %, 16 % respectively. However increase of turn-off time in proposed structures are negligible.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.67-68
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• 2008

In this study we have developed a packaged silicon carbide power diode with blocking voltage of 2kV. PiN diodes with 7 field limiting rings (FLRs) as an edge termination were fabricated on a 4H-SiC wafer with $30{\mu}m$-thick n-epilayer with donor concentration of $1.6\times10^{15}cm^{-3}$. From packaged PiN diode testing, we obtained reverse blocking voltage of 2kV, forward voltage drop of 4.35V at 100A/$cm^2$, on-resistance of $6.6m{\Omega}cm^2$, and about 8 nanosec reverse recovery time. These properties give a potential for the power system application.