• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.174-178
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• 2007

The cleaning process to remove small particles, ions, and other polluted sources is one of the major parts in the recent semiconductor industry because it can cause fatal errors on the quality of the final products. According to the other reports, the major factors of bath's fluid motion are the cleaning method, nozzle, the geometry (of bath, guide and wafer), and the position (of guide and wafer). So to enhance cleaning efficiency in the bath, these factors must be controlled. The purpose of this study is to analyze and visualize fluid motion in the cleaning bath as basic data for designing the nozzle system and finding the process control parameters. For that, we used the general CFD code FLUENT.

• Korean Journal of Materials Research
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• v.16 no.2
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• pp.80-84
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• 2006

The removal efficiency of Cu and Fe contaminants on the silicon wafer surface was examined to investigate the effect of cleaning solutions on the behavior of metallic impurities. Silicon wafers were intentionally contaminated with Cu and Fe solutions by spin coating and cleaned in different types of cleaning solutions based on $NH_4OH/H_2O_2/H_2O\;(SC1),\;H_2O_2/HCl/H_2O$ (SC2), and/or HCl/$H_2O$ (m-SC2) mixtures. The concentration of metallic contaminants on the silicon wafer surface before and after cleaning was analyzed by vapor phase decomposition/inductively coupled plasma-mass spectrometry (VPD/ICP-MS). Cu ions were effectively removed both in alkali (SC1) and in acid (SC2) based solutions. When $H_2O_2$ was not added to SC2 solution like m-SC2, the removal efficiency of Cu impurities was decreased drastically. The efficiency of Cu ions in SC1 was not changed by increasing cleaning temperature. Fe ions were soluble only in acid solution like SC2 or m-SC2 solution. The removal efficiencies of Fe ions in acid solutions were enhanced by increasing cleaning temperature. It is found that the behavior of metallic contaminants as Cu and Fe from silicon surfaces in cleaning solutions could be explained in terms of Pourbaix diagram.

• Journal of Welding and Joining
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• v.19 no.3
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• pp.305-310
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• 2001

UBM-coated Si-wafer was fluxlessly soldered with glass substrate in $N_2$ atmosphere using plasma cleaning method. The bulk Sn-37wt.%Pb solder was rolled to the sheet of $100\mu\textrm{m}$ thickness in order to bond a solder disk by fluxless 1st reflow process. The oxide layer on the solder surface was analysed by AES(Auger Electron Spectroscopy). Through rolling, the oxide layer on the solder surface became thin, and it was possible to bond a solder disk on the Si-wafer with fluxless process in $N_2$ gas. The Si-wafer with a solder disk was plasma-cleaned in order to remove oxide layer formed during 1st reflow and soldered to glass by 2nd reflow process without flux in $N_2$ atmosphere. The thickness of oxide layer decreased with increasing plasma power and cleaning time. The optimum plasma cleaning condition for soldering was 500W 12min. The joint was sound and the thicknesses of intermetallic compounds were less than $1\mu\textrm{m}$.

• Journal of Korea Multimedia Society
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• v.13 no.3
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• pp.400-409
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• 2010

This paper presents a position error recognition system when the wafer is mounted in cleaning equipment among the wafer manufacturing processes. The proposed system is to enhance the performance in cost and reliability by preventing the wafer cleaning system from damaging by alerting it when it is put in correct position. The key algorithms are the calibration method between image acquired from camera and physical wafer, a infrared lighting and the design of the filter, and the extraction of wafer boundary and the position error recognition resulting from generation of circle based on least square method. The system is to install in-line process using high reliable and high accurate position recognition. The experimental results show that the performance is good in detecting errors within tolerance.

• Air Cleaning Technology
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• v.12 no.1 s.44
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• pp.55-80
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• 1999

• Air Cleaning Technology
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• v.14 no.4 s.55
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• pp.40-59
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• 2001

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1880-1884
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• 2008

Cleaning is required following CMP (chemical mechanical planarization) to remove particles. The minimization of particle residue is required with each successive technology generation, and the cleaning of wafers becomes more complicated. In copper damascene process for interconnection structure, it utilizes 2-steop CMP consists of Cu CMP and barrier CMP. Such a 2-steps CMP process leaves a lot of abrasive particles on the wafer surface, cleaning is required to remove abrasive particles. In this study, the buffing is performed various conditions as a cleaning process. The buffing process combined mechanical cleaning by friction between a wafer and a buffing pad and chemical cleaning by buffing solution consists of tetramethyl ammonium hydroxide (TMAH)/benzotriazole(BTA).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.364-365
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• 2006

Transverse some wave was generated by T type waveguide for single wafer cleaning application T type megasonic waveguide was analyzed by acoustic pressure measurements and particle removal efficiency. Compared to conventional longitudinal waves, not like longitudinal waves, transverse waves showed changes of direction and phase which increased the cleaning efficiency.

• Laser Solutions
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• v.5 no.2
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• pp.9-15
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• 2002

Basic principles and unique characteristics of laser-induced shock cleaning have been described compared to a conventional laser cleaning method and the removal of small tungsten particles from silicon wafer surfaces was attempted using both methods. It was found that the conventional laser cleaning was not feasible to remove the tungsten particles whereas a successful removal of the particles was carried out by the laser-induced shock waves. From the quantitative analysis using a surface scanner, the average removal efficiency of the particles was more than 98% where smaller particles were slightly more difficult to remove probably due to the increased adhesion force with a decrease of the particle size. It was also seen that the gap distance between the laser focus and the wafer surface is an important processing parameter since the removal efficiency is strongly dependent on the gap distance.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1005-1006
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• 2013