• Korean Journal of Optics and Photonics
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• v.8 no.6
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• pp.500-505
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• 1997

Experimental amorphous photodiode is fabricated on CMOS IC using a-Si:H p-i-n structure. Amorphous photodiode is scuccessfully integrated on CMOS IC using amorphous Si produced by PECVD system. The PECVD system can deposit a-Si:H at low temperature so that photodiode can be integrated with CMOS IC structure without any process incompatibility. The fabricated amorphous photodiode has a breakdown voltage of below -20 V, a leakage current of about 1 $\mu\textrm{A}$, and turn-on voltage of 0.6~0.8 V. It is demonstrated that the photocurrent of optical signal can be turned on and off by a small voltage and the fabricated amorphous p-i-n photodiode can be used as an optical switch.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1938-1940
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• 1999

Trench-Gate structures are proposed to improve the breakdown voltage of LDMOS as well as the second breakdown under forward biased gate. Two dimensional device simulator PISCES II has been used to explain the effects of the drift layer thickness on the breakdown voltage of the conventional LDMOS and Trench Gate LDMOS in terms of potential contour lines. The Trench Gate structure has shown improvements in the breakdown voltage by about 44% and 84% for $V_G$=0 V and $V_G$=15 V respectively.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.5
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• pp.299-301
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• 2000

Analytical expression for the breakdown voltage of the gated diodes were derived as f function of doping concentration and gate voltage, and verified by numerical simulations using ATLAS. The analytical results are in good agreement with simulation results within 5% error when the gate voltage changes from -50V to 130V in case of ND = $1\times1015 cm^{-3}$ and within 10% error when the doping concentration is changed from $5\times1014 cm^{-3}\; to\; 2\times1015 cm6{-3}$, respectively.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.1
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• pp.18-22
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• 2005

We have proposed and fabricated a dual gate AlGaN/GaN high electron mobility transistor (HEMT), which exhibits the low leakage current and the high breakdown voltage for the high voltage switching applications. The additional gate between the main gate and the drain is specially designed in order to decrease the electric field concentration at the drain-side of the main gate. The leakage current of the proposed HEMT is decreased considerably and the breakdown voltage increases without sacrificing any other electric characteristics such as the transconductance and the drain current. The experimental results show that the breakdown voltage and the leakage current of proposed HEMT are 362 V and 75 nA while those of the conventional HEMT are 196 V and 428 nA, respectively.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1152-1155
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• 1995

An analytic model for the optimum design of the power MOSFET considering the degradation of the breakdown voltage by the three dimensional effect is proposed. The proposed method gives the optimum design parameters such as the lateral radius of window curvature and the doping concentration of the epi-layer, which does not minimize the on-resistance but also maintains the required breakdown voltage. The analytical results are verified by the quasi 3D simulation tools, MEDICI, and it is found that the proposed method may be a good guideline for the design of power MOSFET.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.4
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• pp.246-248
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• 2000

Closed-form expressions for the temperature dependent breakdown voltage and the on-resistance of the Si power MOSFETs were derived by employing effective temperature dependent ionization coefficient for electrons and holes. The breakdown voltage increases by 20% and the on-resistance increases 2 times when the temperature increases from 300 K to 423 K. The analytic results normalized to the values at 300 K show good agreement with the experimental data of Motorola within 3.5% and 7% for the breakdown voltage and the on-resistance, respectively.

• Journal of the Korean Vacuum Society
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• v.4 no.1
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• pp.46-50
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• 1995

물성을 달리한 $\alpha$-Si을 사용하여 MIM(Metal-Insulator-Metal)구조의 antifuse들을 제작하고, 물성의 변화에 따른 전기적 특성의 변화를 조사하였다. $\alpha$-Si은 PECVD (Plasma Enhanced Chemical Vapor Deposition)방법으로 증착하였으며, 물성은 RF power를 달리하여 변화시켰다. $\alpha$-Si MIM구조의 antifuse를 프로그램할 때 생기는 failure rate를 줄이기 위해 전극 사이에 삽입되는 $\alpha$-Si의 contact hole 크기와 개수를 변화시켜 보았다. MIM antifuse는 contact hole이 2개 이상일 때 failure rate가 10% 이내로 줄었으며, 프로그래밍 전류는 거의 변화가 없었다. 항복전압은 10-11V범위에 집중적으로 분포하였으며, 5V에서의 누설전류는 contact hole의 수가 증가함에 따라 커짐을 알았다.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.8
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• pp.38-43
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• 1998

An analytical model for the surface field distribution of the RESURF (reduced surface field)LD(lateral double-diffused) MOS is presented in terms of the doping concentration, the thickness of the n epi layer, the p substrate concentration, and the epi layer length. The reuslts are used to determine the breakdown voltage due to the surface field as a function of the epi layer length. The maximum breakdown voltage of the device is found to be that of the vertical n$^{+}$n$^{[-10]}$ p$^{[-10]}$ junction. Analytical results of the breakdown voltage vs. the epi layer length agree well with the numerical simulation results using MEDICI.I.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1448-1450
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• 1994

The breakdown voltages of punchthrough-mode diodes with cylindrical junction are analytically calculated, The proposed method, which is based on th Gauss's law, estimates the lateral expansion of the depletion region as well as the electric field and the charge distribution. The proposed method is given in terms of epitaxial layer width, the epitaxial layer doping concentration, and curvature radius of the junction edge. The calculation results agree well with the MEDICI simulation results for various device parameters.

• Proceedings of the KIEE Conference
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• 2008.10a
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• pp.179-180
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• 2008

Approximate equations for cylindrical breakdown voltages of planar pn junctions are proposed and verified. The equations show good agreement with the Baliga's results for rj/Wpp${\leq}0.3$ and with numerical results for rj/Wpp${\geq}0.3$ within 1 % error. Sensitivity of the breakdown voltage with respect to the doping concentrations is successfully derived using the approximate equations. The sensitivity formula can be utilized in the area of tolerance design of power semiconductor devices.