• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.747-748
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• 2008

• 반도체디스플레이기술학회지
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• 제2권2호
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• pp.9-15
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• 2003

This paper proposes a thickness measurement method of silicon-oxide and poly-silicon film deposited on 12" silicon wafer for spin etcher. Halogen lamp is used as a light source for generating a wide-band spectrum, which is guided and focused on the wafer surface through a optical fiber cable. Interference signal from the film is detected by optical sensor to determine the thickness of the film using spectrum analysis and several signal processing techniques including curve-fitting and adaptive filtering. Test wafers with three kinds of priori-known films, polysilicon(300 nm), silicon-oxide(500 nm) and silicon-oxide(600 nm), are measured while the wafer is spinning at 20 Hz and DI water flowing on the wafer surface. From experiment results the algorithm presented in the paper is proved to be effective with accuracy of maximum 0.8% error.rror.

• 한국결정성장학회지
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• 제20권5호
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• pp.216-220
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• 2010

Si(100) wafer와 $SiO_2$/Si(100) 웨이퍼에 증착된 NiFe 합금 박막의 결정상과 자기적 특성을 비교하고자 동시 스퍼터링법을 이용하여 두 기판 위에 150 nm의 박막을 제조하여 그의 상변화와 자기적 특성을 XRD, FE-SEM, VSM으로 비교하였다. 두 기판 위에 증착된 NiFe 박막은 BCC상으로 증착되었으나 $400^{\circ}C$에서 2시간 열처리를 한 결과 BCC에서 FCC로의 상전이가 일어나는 것을 관찰 할 수 있었으며 Si(100) wafer위에 증착된 박막에서는 $500^{\circ}C$에서 열처리 후에도 BCC와 FCC가 혼재하여 나타나는 것을 알 수 있었다. $450^{\circ}C$에서 열처리 하였을 때 각형비가 가장 높았으며 포화자화는 0.0118 emu로 나타나고 있었다. $500^{\circ}C$ 이상의 온도에서는 상전이로 인해 포화자화가 급격히 감소하는 것을 볼 수 있었다.

• 반도체디스플레이기술학회지
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• 제9권2호
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• pp.21-25
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• 2010

In response to the industrial needs for automated handling of very thin solar cell wafers, this paper presents the design concept for the individual wafer separation from the stacked wafers by utilizing continuous water jet. The experimental apparatus for automated wafer separation was constructed and it includes the water jet system and the microprocessor controlled wafer stack advancing system. Through a series of tests, the performance of the proposed design is quantified into the success rate of single wafer separation and the rapidity of processing wafer stack. Also, the inclination angle of wafer equipped cartridge and the water jet flowrate are found to be important parameters to be considered for process optimization. The proposed design shows the concept for fast and efficient processing of wafer separation and can be implemented in the automated manufacturing of silicon based solar cell wafers.

• 전자공학회논문지A
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• 제32A권3호
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• pp.134-142
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• 1995

We discovered that each distinct shape of the roof-shaped peaks of (111) facets, which are generated on (110) cross-section of the directly bonded (100) silicon wafer pairs after KOH etching, can be mapped to one of three conditions of the interfacial oxide existing at the bonding interface as follows. That is, thick solid line can be mapped to stabilization, thin solid line to disintegration, and thin broken line to spheroidization. also we confirmed that most of the interfacial oxides of a well-aligned wafer pairs were disintegrated and spheroidized through high-temperature annealing process above 900$^{\circ}$C while the oxide was stabilized persistently when two wafers are bonded rotationally around their common axis perpendicular to the wafer planes.

• 한국정밀공학회지
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• 제31권10호
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• pp.865-871
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• 2014

Paradigm shift to 3-D chip stacking in electronic packaging has induced a lot of integration challenges due to the reduction in wafer thickness and pitch size. This study presents a hybrid bonding technology by self-alignment effect in order to improve the flip chip bonding accuracy with ultra-thin wafer. Optimization of Cu pillar bump formation and evaluation of various factors on self-alignment effect was performed. As a result, highly-improved bonding accuracy of thin wafer with a $50{\mu}m$ of thickness was achieved without solder bridging or bump misalignment by applying reflow process after thermo-compression bonding process. Reflow process caused the inherently-misaligned micro-bump to be aligned due to the interface tension between Si die and solder bump. Control of solder bump volume with respect to the chip dimension was the critical factor for self-alignment effect. This study indicated that bump design for 3D packaging could be tuned for the improvement of micro-bonding quality.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.863-864
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• 2011

• 한국재료학회지
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• 제25권1호
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• pp.16-20
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• 2015

In this study, in order to improve the efficiency of n-type monocrystalline solar cells with an Alu-cell structure, we investigate the effect of the amount of Al paste in thin n-type monocrystalline wafers with thicknesses of $120{\mu}m$, $130{\mu}m$, $140{\mu}m$. Formation of the Al doped $p^+$ layer and wafer bowing occurred from the formation process of the Al back electrode was analyzed. Changing the amount of Al paste increased the thickness of the Al doped $p^+$ layer, and sheet resistivity decreased; however, wafer bowing increased due to the thermal expansion coefficient between the Al paste and the c-Si wafer. With the application of $5.34mg/cm^2$ of Al paste, wafer bowing in a thickness of $140{\mu}m$ reached a maximum of 2.9 mm and wafer bowing in a thickness of $120{\mu}m$ reached a maximum of 4 mm. The study's results suggest that when considering uniformity and thickness of an Al doped $p^+$ layer, sheet resistivity, and wafer bowing, the appropriate amount of Al paste for formation of the Al back electrode is $4.72mg/cm^2$ in a wafer with a thickness of $120{\mu}m$.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1448-1452
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• 2003

A scratch tester was developed to evaluate the adhesive strength at interface between thin-film and substrate(silicon wafer). Under force control, the scratch tester can measure the normal and the tangential forces simultaneously as the probe tip of the equipment approaches to the interface between thin-film and substrate of wafer. The capacity of each component of force sensor is 0.1 N ${\sim}$ 100 N. In addition, the tester can detect the signal of elastic wave from AE sensor(frequency range of 900 kHz) attached to the probe tip and evaluate the bonding strength of interface. Using the developed scratch tester, the feasibility test was performed to evaluate the adhesive strength of thin-film.

• 통합자연과학논문집
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• 제3권4호
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• pp.219-225
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• 2010

On the surface of mesoporous silica thin films (MSTF) which were fabricated by sol-gel approach there are existences of water and three different silanol types including chained, germinal and isolated silanol. Their amounts changes as a function of aging time of used sol solution, as confirmed by FT-IR. The adsorbed water generates ionic carriers such as H+ and OH- and passivates the Si dangling bonds at the interface of silicon wafer-MSTF. The ionic carriers can not only transport across the thickness of thin film to enhance the leakage current but also diffuse toward the silicon wafer-MSTF interface to depassivate Si dangling bonds. On the other hand, chained silanols or germinal silanols promote the moisture adsorption of MSTF and tend to form strongly hydrogen bonded systems with adsorbed water molecules resulting in very high dielectric constant. Isolated silanol, on the contrary, affects less on electrical properties of thin film.