• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.844-847
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• 2001

In this work, transient characteristics of the Non-Punch Through(NPT) Insulated Gate Bipolar Transistor(IGBT) has been studied. we has analyzed with lifetimes excess minority carrier injected into N-dirft, base region of IGBT's BJT part and accumulated charge of on-state which affected swiching characteristic. In this paper, excess minority carrier and charge distribution in active base region is expressed analytically. This analysis proposed optical trade-off between lifetimes and accumulated charge for decreasing switching losses because charge result in switching loss when device was tuned off.

• Journal of Power Electronics
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• v.16 no.2
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• pp.778-785
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• 2016

An excess carrier lifetime extraction method is derived for physics-based insulated gate bipolar transistor (IGBT) models with consideration of the latest development in IGBT modeling. On the basis of the 2D mixed-mode Sentaurus simulation, the clamp turn-off test is simulated to obtain the tail current. The proposed excess carrier lifetime extraction method is then performed using the simulated data. The comparison between the extracted results and actual lifetime directly obtained from the numerical device model precisely demonstrates the accuracy of the proposed method.

• Bulletin of the Korean Chemical Society
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• v.19 no.11
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• pp.1172-1174
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• 1998

Spatial(radial and height) distributions of excited argon species are measured for an inductively coupled plasma under five operating conditions: 1) no carrier gas, 2) carrier gas without aerosol, 3) carrier gas with desolvated aerosol, 4) carrier gas with aerosol, 5) carrier gas with aerosol and excess lithium. A complete RF power mapping of argon excited states is obtained. The excited states of argon for a typical analytical torch rapidly diffuse towards the center in the higher region of the plasma. The presence of excess lithium makes no significant change in the excited states of argon. The increase in the RF power increases the intensity of argon excited states uniformly across the radial coordinate.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.292-295
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• 2002

In this work, transient characteristics of NPT(Non Punch Through)-IGBT(Insulated Gate Bipolar Transistor) have been studied with different temperatures analytically. Power losses are caused by heat generated in MIT-IGBT for steady state and transient state conditions. We therefore have focused on the analysis of excess carrier concentration and excess charge injected into N-drift layer with different temperatures and have obtained anode voltage drop during turn-off with lifetime of 2.4[${\mu}$s].

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.405-408
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• 2004

In this work, Analytical model for voltage and current characteristics of NPT(Non-PunchThrough) IGBT(Insulated Gate Bipolar Transistor) was represented. voltage and current characteristics models were based on prediction on power loss of NPT IGBT during transient condition. For Analytical current model, excess carrier concentration and accumulated charge in active base width was analyzed with time variance. Analytical models were simulated by varying lifetime of excess minority carrier.

• Journal of the Korean Chemical Society
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• v.30 no.3
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• pp.327-332
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• 1986

Spatial (radial and height) distribution of electron number density is measured for an inductively coupled plasma under five operating conditions: (1) no carrier gas, (2) carrier gas without aerosel, (3) carrier gas with aerosol, (4) carrier gas with desolvated aerosol, and (5) carrier gas with aerosol and excess lithium. A complete RF power mapping of electron density is obtained. The plasma electrons for a typical analytical torch are observed to be hollow at the radial center in the region close to the induction coil, but diffuse rapidly toward the center in the higher region of the plasma. The presence of excess Li makes no significant change in the electron density profiles. The increases in the RF power levels increase the values of electron density uniformly across the radial coordinate.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.9
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• pp.8-13
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• 2008

Noise in homogeneous extrinsic semiconductor samples is calculated due to distributed diffusion noise sources. As the length of the device shrinks at a fixed bias voltage, the ac-wise short-circuit noise current shows excess noise as well as thermal noise spectra. This excess noise behaves like a full shot noise when the channel length becomes very small compared with the extrinsic Debye length. For the first time, the analytic formula of the excess noise in extrinsic semiconductors from velocity-fluctuation noise sources is given for finite frequencies. This formula shows the interplay between transit time, dielectric relaxation time, and velocity relaxation time in determining the terminal noise current as well as the carrier density fluctuation. As frequency increases, the power spectral density of the excess noise rolls off. This formula sheds light on noise in nanoscale MOSFETs where quasi-ballistic transport plays an important role in carrier transport and noise.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.4
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• pp.581-586
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• 1998

We investigated the effect of mechanical back side damage in Czochralski grown silicon wafer. The intensity of mechanical damage was evaluated by minority carrier recombination lifetime by laser excitation/microwave reflection photoconductivity decay method, degree of X-ray diffuse scattering, X-ray section topography, and wet oxidation/preferential etching methods. The data indicate that the higher the mechanical damage intensity, the lower the minority carrier lifetime, and the magnitude of diffuse scattering and X-ray excess intensity increased proportionally, and it was at Grade 1:Grade 2:Grade 3=1:7:18.4 that the normalized relative quantization ratio of excess intensity in damaged wafer was calculated, which are normalized to the excess intensity from sample Grade 1.

• Transactions of Materials Processing
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• v.14 no.2 s.74
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• pp.153-159
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• 2005

Design modification of the stamping die for the upper member of a front end module carrier is carried out in order to improve the surface quality of the final product. The small inferiority induced by wrinkling near the wall of the upper member has been inspected after the draw-forming process. The finite element analysis is pursued with the whole geometry in order to consider the complicated shape. The simulation shows that the excess metal is developed by the irregular contact of the blank the tool and it remains after the final stroke. This paper proposes two guidelines for the modification. One is to add the draw-bead near the critical region in order to increase the draw-in force. The other is to modify the tool shape such as the forming shape at the wall in order to absorb the excess metal before the final stroke. Simulation results show that the proposed guidelines both guarantee the improved surface quality.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.374-377
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• 2003

In this paper, turn on characteristics of (Punch-Through Insulated Gate Bipolar Transistor) PT-IGBT has been studied. Based on the transient power loss, turn on charges first base to collector capacitance. Furthermore we present the charge variation in the base including n+ buffer layer to express the transient turn-on characteristics of the device.