• Electronic Materials Letters
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• v.14 no.6
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• pp.774-783
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• 2018

Full maximum-entropy mobility-spectrum analysis (FMEMSA) is the best algorithm among mobility spectrum analyses by which we can obtain a set of partial-conductivities associated with mobility values (mobility spectrum) by analyzing magnetic-field-dependent conductivity-tensors. However, it is restricted to a direct band-gap semiconductor and should be modified for materials with other band structures. We developed the modified version of FMEMSA which is appropriate for a material with a single anisotropic valley, or an indirect-band-gap semiconductor quantum-well with a single non-degenerate conduction-band valley e.g., (110)-oriented AlAs quantum wells with a single anisotropic valley. To demonstrate the reliability of the modified version, we applied it to several sets of synthetic measurement datasets. The results demonstrated that, unlike existing FMEMSA, the modified version could produce accurate mobility spectra of materials with a single anisotropic valley.

• Journal of the Semiconductor & Display Technology
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• v.23 no.2
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• pp.92-99
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• 2024

As semiconductor processes require several nanometers precision, the importance of motor control is increasing in semiconductor equipment. Due to unpredictable uncertainties such as friction and mechanical vibrations achieving precise position control in semiconductor processes is challenging. The internal model principle-based controller is a control technique that ensures robust steady-state performance by incorporating a model of the reference and disturbance. The disturbance observer-based controller is a prominent robust control technique implemented to cope with various nonlinearities and uncertainties. Provided that the two controllers can be designed to exhibit equivalent performance under certain conditions, this paper demonstrates through experiments that they yield identical results for the case of a BLDC position control problem. The experimental results also indicate that they can offer enhanced robustness compared with the conventional PID controller in the presence of a time-varying disturbance.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.5
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• pp.6-11
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• 2011

We have developed dissolved ozone decompose system in the used ozonated water for the semiconductor and LCD fabrication processes, which will be base of obtaining core process technology in the high performance, low price semiconductor and LCD fabrications. Using this technology, it is possible for the semiconductor wafer and LCD planer to process more rapid and chip, and productivity will be improved.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.5
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• pp.350-354
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• 2020

In this study, a pressure sensor for each displacement was fabricated based on the silicon-based pressure sensor obtained through simulation results. Wires were bonded to the pressure sensor, and a piezoresistive pressure sensor was inserted into the printed circuit board (PCB) base by directly connecting a micro-electro-mechanical system (MEMS) sensor and a readout integrated circuit (ROIC) for signal processing. In addition, to prevent exposure, a non-conductive liquid silicone was injected into the sensor and the entire ROIC using a pipette. The packaging proceeded to block from the outside. Performing such packaging, comparing simple contact with strong contact, and confirming that the measured pulse wavelength appears accurately.

• Journal of the Semiconductor & Display Technology
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• v.4 no.1 s.10
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• pp.17-21
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• 2005

We presented a new method to obtain four speckle interferograms with relative phase shift of $\pi$/2 by passive devices such as waveplate and polarizer, calculate the phase at each point of the speckle interferogram in shearography using Wollaston prism, which can be applied to the deformation evaluation of semiconductor devices, and theoretically demonstrated the feasibility of the proposed method by Jones matrix.

• Journal of the Semiconductor & Display Technology
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• v.2 no.3
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• pp.13-18
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• 2003

A remote monitoring system of the semiconductor equipment is used to monitor or control operations of the equipment. Most of the conventional monitoring systems are based on the client-server model with the general purpose PC. Basically, it implies the difficulties in the system reliability and cost down due to its size and complexity. To overcome these difficulties, we suggest an embedded web server which is based on the low-cost microprocessor. It is designed for the monitoring or controlling a dedicated equipment only. To evaluate the feasibility of the suggested embedded web server, we have implemented a test-board with ATMega103 and programmed the basic modules using the AVR-GCC. Finally, we have tested its operations on the MS Explorer 6.0 environment.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.3
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• pp.443-451
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• 2001

This paper addresses an on-line scheduling method for track systems in semiconductor fabrication. A track system is a clustered equipment performing photolithography process in semiconductor fabrication. Trends toward high automation and flexibility in the track systems accelerate the necessity of the intelligent controller that can guarantee reliability and optimize productivity of the track systems. This paper proposes an-efficient on-line scheduling method that can avoid deadlock inherent to track systems and optimize the productivity. We employ two procedures for the on-line scheduling. First, we define potential deadlock set to apply deadlock avoidance policy efficiently. After introducing the potential deadlock set, we propose a deadlock avoidance policy using an on-line Gantt chart, which can generate optimal near-optimal schedule without deadlock. The proposed on-line scheduling method is shown to be efficient in handling deadlock inherent to the track systems through simulation.

• Journal of the Korea Safety Management & Science
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• v.8 no.1
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• pp.17-26
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• 2006

Basis frame-work's base in a semiconductor industry have gas, chemical, electricity and various facilities in bring to it. That it is a foundation by fire, power failure, blast, spill of toxicant huge by large size accident human and physical loss and damage because it can bring this efficient, connect with each kind mechanical, physical thing to prevent usefully need that control finding achievement factor of human factor of human action. Large size accident in a semiconductor industry to machine and human and it is involved that present, in system by safety interlock defect of machine is conclusion for error of behaviour. What is not construing in this study, do safety in a semiconductor industry to do improvement. Control human error analyzes in human control with and considers mechanical element and several elements. Also, apply achievement factor using O'conner Model by control method of human error. In analyze by failure mode effect using actuality example.

• Journal of the Semiconductor & Display Technology
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• v.16 no.1
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• pp.70-74
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• 2017

To research the electrical properties of ZnS thin films with various annealing conditions, ZnS was prepared by RF magnetron sputtering system and annealed in a vacuum for 10 minutes. All films were analyzed by the XRD, PL and I-V measurement system. The XRD pattern of ZnS film annealed at $100^{\circ}C$ was shifted to lower 2 theta because of the formation of a depletion region at the interface between a substrate and ZnS thin film, and the capacitance was abruptly increased. However, the pattern of XRD of ZnS film annealed at $100^{\circ}C$ with a Schottky contact was showed the amorphous structure, and the current-voltage characteristics were non-linearly observed by the Schottky contact.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.12
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• pp.1072-1080
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• 2013

In a the present day, many vision inspection techniques are used in productive industrial areas. In particular, in the semiconductor industry the vision inspection system for wafers is a very important system. Also, inspection techniques for semiconductor wafer production are required to ensure high precision and fast inspection. In order to achieve these objectives, parallel processing of the inspection algorithm is essentially needed. In this paper, we propose the GPU (Graphical Processing Unit)-based parallel processing algorithm for the fast inspection of semiconductor wafers. The proposed algorithm is implemented on GPU boards made by NVIDIA Company. The defect detection performance of the proposed algorithm implemented on the GPU is the same as if by a single CPU, but the execution time of the proposed method is about 210 times faster than the one with a single CPU.