• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.358-358
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• 2000

An iterative learning control technique based on a linear quadratic optimal criterion is proposed for temperature uniformity control of a silicon wafer in rapid thermal processing.

• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.81-86
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• 2023

Recently, there has been an increased demand for light-emitting diode (LED) due to the growing emphasis on environmental protection. However, the use of GaN-based sapphire in LED manufacturing leads to the generation of defects, such as dislocations caused by lattice mismatch, which ultimately reduces the luminous efficiency of LEDs. Moreover, most inspections for LED semiconductors focus on evaluating the luminous efficiency after packaging. To address these challenges, this paper aims to detect defects at the wafer stage, which could potentially improve the manufacturing process and reduce costs. To achieve this, image processing and deep learning-based defect detection techniques for Sapphire Epi-Wafer used in Green LED manufacturing were developed and compared. Through performance evaluation of each algorithm, it was found that the deep learning approach outperformed the image processing approach in terms of detection accuracy and efficiency.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.2
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• pp.149-157
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• 2008

During CVD process of semiconductor wafer fabrication, maintaining the uniformity of temperature distribution at wafer top surface is one of the key factors affecting the quality of final products. Effect of contact conductance between wafer and hot plate on predicted temperature of wafer was investigated. The validity of opaque wafer assumption was also examined by comparing the predicted results with Discrete Ordinate solutions accounting for semitransparent radiative characteristics of silicon. As the contact conductance increases predicted wafer temperature increases and the differences between maximum and minimum temperatures within wafer and between wafer and hot plate top surface temperatures decrease. The opaque assumption always overpredicted the wafer temperature compared to semitransparent calculation. The influences of surrounding reactor inner wall temperature and hot plate configuration are then discussed.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2005.09a
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• pp.89-110
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• 2005

A new 3D integration technology using wafer-to-wafer and chip-to-wafer stacking method was described. It was demonstrated that 3D microprocessor, 3D shared memory, 3D image processing chip and 3D artificial retina chip fabricated using 3D integration technology were successfully operated. The possibility of applying 3D image processing chip and 3D artificial retina chip to Robot's eye was investigated. The possibility of implanting 3D artificial retina chip into human eye was investigated.

• Journal of the Korea Society for Simulation
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• v.12 no.3
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• pp.13-20
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• 2003

Semiconductor Manufacturing has emerged as one of the most important world industries. Even with the highly automated and precisely monitored facilities used to process the complex manufacturing steps in a near particle free environment, processing variations in wafer fabrication still exist. The causes of these variations may arise from equipment malfunctions, delicate and difficult processing steps, or human mistakes. In this paper, we could specify the cause stage and the cause equipment and take countermeasures at a speed by the conventional method, without depending on the experience and skills of the engineer

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.5
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• pp.419-424
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• 2002

After the patterning and probe process of wafer have been achieved, the dicing processing is necessary to separate chips from a wafer. The dicing process cuts a semiconductor wafer to lengthwise and crosswise directions to make many chips. The existing general dicing method is the mechanical cutting using a narrow circular rotating blade impregnated diamond particles or laser cutting. Inferior goods can be made by the mechanical or laser cutting unless several parameters such as blade, wafer, cutting water and cutting conditions are properly set. Moreover, we can not apply these general dicing method to that of GaN wafer, because the GaN wafer is harder than general semiconductor wafers such as GaAs, GaAsP, AIGaAs and so forth. In order to overcome these problems, this paper describes a new wafer dicing method using fixed diamond scriber and precision servo mechanism.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.8
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• pp.11-16
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• 2008

In this paper, firstly we made of the rapid thermal processor equipment with the specifically useful structure to measure wafer stress. Secondly we made of the laser interferometry to inspect the wafer surface curvature based on the large deformation theory. And then the wafer surface fringe image was obtained by experiment, and the full field stress distribution of wafer surface comes into view by signal processing with thining and pitch mapping. After wafer was ground by 1mm and polished from the back side to get easily deformation, and it was heated by three to four times thermal treatments at about 1000 degree temperature. Finally the severe deformation between wafer before and after the heat treatment was shown.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.5
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• pp.31-40
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• 2005

In this study, we study measurement of wafer processing throughput and sequence simulation of single wafer type for wafer cleaning equipments that were used for etching, cleaning and polishing of wafer. Based on finite state machine, simulation model was built with identification of robot's status according to scheduling algorithm. Moreover, through performance of simulation as above, throughput per hour of cleaning equipment was measured. By the simulation method that are proposed in this paper, we could measure the wafer throughput per hour according to recipe and robot motion speed, and find optimal recipe and moving sequence of robot that maximize the throughput.

• Journal of the Semiconductor & Display Technology
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• v.16 no.1
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• pp.29-33
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• 2017

This paper presents a development of vision aligner with three channels for the wafer and plate bonding machine in manufacturing of LED. The developed vision aligner consists of three cameras and performs wafer alignment of rotation and translation, flipped wafer detection, and UV Tape detection on the target wafer and plate. Normally the process step of wafer bonding is not defined by standards in semiconductor's manufacturing which steps are used depends on the wafer types so, a lot of processing steps has many unexpected problems by the workers and environment of manufacturing such as the above mentioned. For the mass production, the machine operation related to production time and worker's safety so the operation process should be operated at one time with considering of unexpected problem. The developed system solved the 4 kinds of unexpected problems and it will apply on the massproduction environment.

• Laser Solutions
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• v.8 no.2
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• pp.7-12
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• 2005

The material processing of UV nanosecond pulse laser cannot be avoided the material shape change and contamination caused by interaction of base material and laser beam. Nowadays, ultra short pulse laser shorter than nanosecond pulse duration is used to overcome this problem. The advantages of this laser are no heat transfer, no splashing material, no left material to the adjacent material. Because of these characteristics, it is so suitable for micro material processing. The processing of sapphire wafer was done by UV 355nm, green 532nm, IR 1064nm. X-Y motorized stage is installed to investigate the proper laser beam irradiation speed and cycles. Also, laser beam fluence and peak power are calculated.