• 반도체디스플레이기술학회지
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• 제10권3호
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• pp.49-52
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• 2011

This paper shows the results of classical molecular dynamics modeling for the interaction between spherical nano abrasive and substrate in chemical mechanical polishing processes. Atomistic modeling was achieved from 3-dimensional molecular dynamics simulations using the Morse potential functions for chemical mechanical polishing. The abrasive dynamics was modeled by three cases, such as slipping, rolling, and rotating. Simulation results showed that the different dynamics of the abrasive results the different features of surfaces. The simulation concerning polishing pad, abrasive particles and the substrate has same results.

• 대한산업공학회지
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• 제35권4호
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• pp.266-279
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• 2009

This paper focuses on the problem of scheduling wafer lots with limited waiting times between pairs of consecutive operations in a semiconductor wafer fabrication facility. For the problem of minimizing total tardiness of orders, we develop a priority rule based scheduling method in which a scheduling decision for an operation is made based on the states of workstations for the operation and its successor or predecessor operation. To evaluate performance of the suggested scheduling method, we perform simulation experiments using real factory data as well as randomly generated data sets. Results of the simulation experiments show that the suggested method performs better than a method suggested in other research and the one that has been used in practice.

• Journal of Power Electronics
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• 제11권3호
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• pp.381-388
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• 2011

This article presents the development of a model for SiC power diodes based on the physics of the semiconductor. The model is able to simulate the behavior of the dynamics of the charges in the N- region based on the stored charge inside the SiC power diode, depending on the working regime of the device (turn-on, on-state, and turn-off). The optimal individual calculation of the ambipolar diffusion length for every phase of commutation allows for solving the ambipolar diffusion equation (ADE) using a very simple approach. By means of this methodology development a set of differential equations that models the main physical phenomena associated with the semiconductor power device are obtained. The model is developed in Pspice with acceptable simulation times and without convergence problems during its implementation.

• 한국산업융합학회 논문집
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• 제24권4_1호
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• pp.411-419
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• 2021

In this study, IGBT_Total_Loss and DIODE_Total_Loss were used to analyze the slope of the junction temperature for each section for temperature and duty variables in order to simply calculate the junction temperature of the power semiconductor (IGBT). As a result of the calculation, IGBT_Max_Junction_Temp and DIODE_Max_Junction_Temp form a proportional relationship with temperature for each duty. This simulation data shows that the power loss of a power semiconductor is calculated in a complex manner according to the current dependence index, voltage dependence index, and temperature coefficient. By applying the slope for each condition and section, the junction temperature of the power semiconductor can be calculated simply.

• Journal of Power Electronics
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• 제12권1호
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• pp.19-23
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• 2012

This paper presents a practical methodology for realistic simulation on reverse characteristics of Wide Bandgap (WBG) SiC and GaN p-n junctions. The adjustment on certain physic-based model parameters, such as the trap density and photo-generation for SiC junction, and impact ionization coefficients and critical field for GaN junction are described. The adjusted parameters were used in Synopsys Medici simulation to obtain a realistic p-n junction avalanche breakdown voltage. The simulation results were verified through benchmarking against independent data reported by others.

• 반도체디스플레이기술학회지
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• 제9권2호
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• pp.27-31
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• 2010

A solenoid actuator characterized by low price, available small size, and convenience is one of the main components of production equipments requiring compact, high-speed actuators. When the response needs to be under few milli-seconds, sensing the position of the actuator is much harder because of the inherent low inertia. Improvement of the required performance of these actuators can be obtained by the simulation using a mathematical model. In this study, the mathematical model is presented and proved by comparing the responses of the actual solenoid and of the simulation. The position of the actual solenoid was measured by the eddy current sensor. The simulation was executed using SIMULINK$^{(R)}$.

• 반도체디스플레이기술학회지
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• 제20권4호
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• pp.141-145
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• 2021

The brightness of the Organic Light Emitting Diode (OLED) display is controlled by thin-film transistors (TFTs). Regardless of the materials and the structures of TFTs, an OLED suffers from the instable threshold voltage (V_th) of a TFT during operation. When designing an OLED pixel with circuit simulation tool such as SPICE, a designer needs to take V_th shift into account to improve the reliability of the circuit and various compensation methods have been proposed. In this paper, the effect of the compensation circuits from two typical OLED pixel circuits proposed in the literature are studied by the transient simulation with a SPICE tool in which the stretched-exponential time dependent V_th shift function is implemented. The simulation results show that the compensation circuits improve the reliability at the beginning of each frame, but V_th shifts from all TFTs in a pixel need to be considered to improve long-time reliability.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2001년도 춘계학술발표강연 및 논문개요집
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• pp.75-75
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• 2001

• Journal of information and communication convergence engineering
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• 제8권4호
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• pp.457-460
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• 2010

we have analyzed tens of Giga pulse signal generation using sideband injection locking scheme. The numerical model for semiconductor lasers under the strong optical injection is based on the Lang's equation and has been extended in order to take into account the simultaneous injection of the multiple sidebands of the current-modulated laser. The numerical simulation results show that the unselected sidebands will affect the optical and RF-spectral characteristics even though the semiconductor laser is locked to the target sidebands.

• 한국산업보건학회지
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• 제32권2호
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• pp.111-115
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• 2022

Objectives: The purpose of this study is to verify whether droplet-induced propagation, the main route of infectious diseases such as COVID-19, can occur in semiconductor FAB (Fabrication), based on research results on general droplet propagation. Methods: Through data surveys droplet propagation was modeled through simulation and experimental case analysis according to general (without mask) and mask-wearing conditions, and the risk of droplet propagation was inferred by reflecting semiconductor FAB operation conditions (air current, air conditioning system, humidity, filter conditions). Results: Based on the results investigated to predict the possibility of spreading infectious diseases in semiconductor FAB, the total amount of droplet propagation (concentration), propagation distance, and virus life in FAB were inferred by reflecting the management parameter of semiconductor FAB. Conclusions: The total amount(concentration) of droplet propagation in the semiconductor fab is most affected by the presence or absence of wearing a mask and the line air dilution rate has some influence. when worn it spreads within 0.35~1m, and since the humidity is constant the virus can survive in the air for up to 3 hours. as a result the semiconductor fab is judged to be and effective space to block virus propagation due to the special environmental condition of a clean room.