• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.8
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• pp.715-718
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• 2008

An in-line wet etch/cleaning system was established for the research and development in wet etch process. The system was equipped with a reverse moving system for the reduction in the size of the in-line wet etch/cleaning system and it was possible for the glass substrate to be moved back and forth and alternated in a wet etch bath. For the comparison of the effect of the normal motion and that of the alternating motion on the in-line wet etch process, indium tin oxide(ITO) pattern was obtained through both wet etch process conditions. The results showed that the alternating motion is not inferior to the normal motion in etch rate and in etch uniformity. It is concluded that the alternating motion is possible to be applied to the in-line etch process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.127-128
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• 2009

CCP방식의 식각에 있어서 CF4/O2 Plasma Etch에 Ar을 첨가함으로써 Etch특성이 어떻게 변화하는지를 조사하였다. FE-SEM를 이용하여 Etch Profile를 측정하였다. 또한 Elipsometer와 Nanospec을 이용하여 Etch rate를 측정하였다. Ar의 비율이 전체의 47%정도를 차지하였을 때까지 Etch Profile이 향상되었다가 그이후로는 다시 감소하는 것을 볼 수 있었다. Ar을 첨가할수록 etch rate은 계속 향상되었다. Ar을 첨가하는 것은 물리적인 식각으로 반응하여 Etch rate의 향상과 적정량의 Ar을 첨가했을 때 Etch profile이 향상되는 결과를 얻었다.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.02a
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• pp.105-106
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• 1998

Evaluation of def3ects by etch-ppit formation was studied. A NaOH(30 mol%) etchant was found useful for etch-ppit developpment on ZnSe-based eppilayers grown on (001) gaAs. And a H3ppO4(85 mol%) was used in order to developp etch-ppits on GaN-base eppilayers grown on (0001) Al2O3 After etch-ppit formation on the surfsce. Transmission Electron Microscoppy(TEM) was cppmdicted. By etch-ppit developpment and TEM observation we could determine the defect typpes by etch-ppit configurfations and found origin of etch-ppit in the cse of ZnSe-based materials. Based uppon these results we can do defect identification by etch-ppit test simpply. In the case of GaN-based materials we could evaluate nanoppippe density. however high density of threading dislocations in GaN eppilayers were not revealed by etch-ppit developpment. Based uppon these results we can evaluate the nanoppippe density which difficult to evaluate using TEM beacause of its small size(diameter). And at ppresent status direct matching of etch-ppit density to dislocation density would make severe mistake.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.5
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• pp.353-360
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• 2012

As semiconductor device technology continuously shrinks, low-open area etch process prevails in front-end etch process, such as contact etch as well as one cylindrical storage (OCS) etch. To eliminate over loaded wafer processing test, it is commonly performed to emply diced small coupons at stage of initiative process development. In nominal etch condition, etch responses of whole wafer test and coupon test may be regarded to provide similar results; however, optical emission spectroscopy (OES) which is frequently utilize to monitor etch chemistry inside the chamber cannot be regarded as the same, especially etch mask is not the same material with wafer chuck. In this experiment, we compared OES data acquired from two cases of etch experiments; one with coupon etch tests mounted on photoresist coated wafer and the other with coupons only on the chuck. We observed different behaviors of OES data from the two sets of experiment, and the analytical results showed that careful investigation should be taken place in OES study, especially in coupon size etch.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.83-83
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• 2009

We studied about the effect of newly developed etchant for spacer etch process in gate patterning. With the 110nm CMOS technology, first, we changed the gate pattern size and investigated the variation of spacer etch profile according to the difference in gate length. Second, thickness of spacer nitride was changed and effect of etch ant on difference in nitride thickness was observed. In addition to these, spacer etch power was added as test item for variation of etch profile. We investigated the etch profiles with SEM and TEM analysis was used for plasma damage check. With these results we could check the process margins for gate patterning which could hold best performance and choose the condition for best spacer etch profile.

• Journal of the Korean institute of surface engineering
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• v.32 no.2
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• pp.83-92
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• 1999

GaN etching was performed using planar inductively coupled $Cl_2$-based plasmas and the effects of main process parameters on the characteristics of the plasmas and their relations to GaN etch rates were studied. Also, the GaN etch mechanism was investigated using a Langmuir probe and optical emission spectroscopy (OES) during the etching, and X-ray photoelectron spectroscopy (XPS) of the etched surfaces. The GaN etch rates increased with the increase of chlorine radical density and ion energy, and a vertical etch profile haying the etch rate close to 4000 $\AA$/min could be obtained. The addition of 10% Ar to $Cl_2$ gas increased the GaN etch rate and the addition of Ar (more than 20%) and HBr generally reduced the GaN etch rate. The GaN etch rate appeared to be more affected by the chemical reaction between Cl radicals and GaN compared to the physical sputtering itself under the sufficient ion bombardments to break GaN bonds.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.436-437
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• 2012

Double patterning technology (DPT) has been suggested as a promising candidates of the next generation lithography technology in FLASH and DRAM manufacturing in sub-40nm technology node. DPT enables to overcome the physical limitation of optical lithography, and it is expected to be continued as long as e-beam lithography takes place in manufacturing. Several different processes for DPT are currently available in practice, and they are litho-litho-etch (LLE), litho-etch-litho-etch (LELE), litho-freeze-litho-etch (LFLE), and self-aligned double patterning (SADP) [1]. The self-aligned approach is regarded as more suitable for mass production, but it requires precise control of sidewall space etch profile for the exact definition of hard mask layer. In this paper, we propose etch end point detection (EPD) in spacer etching to precisely control sidewall profile in SADP. Conventional etch EPD notify the end point after or on-set of a layer being etched is removed, but the EPD in spacer etch should land-off exactly after surface removal while the spacer is still remained. Precise control of real-time in-situ EPD may help to control the size of spacer to realize desired pattern geometry. To demonstrate the capability of spacer-etch EPD, we fabricated metal line structure on silicon dioxide layer and spacer deposition layer with silicon nitride. While blanket etch of the spacer layer takes place in inductively coupled plasma-reactive ion etching (ICP-RIE), in-situ monitoring of plasma chemistry is performed using optical emission spectroscopy (OES), and the acquired data is stored in a local computer. Through offline analysis of the acquired OES data with respect to etch gas and by-product chemistry, a representative EPD time traces signal is derived. We found that the SE-EPD is useful for precise control of spacer etching in DPT, and we are continuously developing real-time SE-EPD methodology employing cumulative sum (CUSUM) control chart [2].

• Restorative Dentistry and Endodontics
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• v.46 no.2
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• pp.30.1-30.13
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• 2021

Objectives: This study was conducted to compare the microleakage and characteristics of the resin-tooth tissue interface between self-etch and etch-and-rinse adhesive systems after 48 hours and 3 months. Materials and Methods: 40 extracted premolar teeth were randomly divided into 2 groups: 1-step self-etch adhesive system - Optibond^TM All-In-One, and 2-step etch-and-rinse adhesive system - Adper^TM Single Bond 2. Both groups were subjected to 500 thermocycles (5℃-55℃) before scanning electron microscope (SEM) analysis or microleakage trial at 48-hour and 3-month time periods. Results: SEM images showed the hybrid layer thickness, diameter, and length of resin tags of the self-etch adhesive (0.42 ± 0.14 ㎛; 1.49 ± 0.45 ㎛; 16.35 ± 14.26 ㎛) were smaller than those of the etch-and-rinse adhesive (4.39 ± 1.52 ㎛; 3.49 ± 1 ㎛; 52.81 ± 35.81 ㎛). In dentin, the microleakage scores of the 2 adhesives were not different in both time periods (48 hours/3 months). However, the microleakage score of etch-and-rinse adhesive increased significantly after 3 months (0.8 ± 0.63 and 1.9 ± 0.88, p < 0.05). Conclusions: The self-etch adhesive exhibited better long-term sealing ability in dentin when compared to that of the etch-and-rinse adhesive. The greater hybrid layer thickness and dimensions of resin tags did not guarantee reliable, long-lasting sealing in the bonding area.

• Journal of Sensor Science and Technology
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• v.32 no.5
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• pp.328-333
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• 2023

This study experimentally verified the etch rate of the SiO₂ sacrificial layer etching process with a single etch hole using vapor-phase hydrogen fluoride (VHF) etching. To fabricate small-sized polysilicon etch holes, both circular and triangular pattern masks were employed. Etch holes were fabricated in the polysilicon thin film on the SiO₂ sacrificial layer, and VHF etching was performed to release the polysilicon thin film. The lateral etch rate was measured for varying etch hole sizes and sacrificial layer thicknesses. Based on the measured results, we obtained an approximate equation for the etch rate as a function of the etch hole size and sacrificial layer thickness. The etch rates obtained in this study can be utilized to minimize structural damage caused by incomplete or excessive etching in sacrificial layer processes. In addition, the results of this study provide insights for optimizing sacrificial layer etching and properly designing the size and spacing of the etch holes. In the future, further research will be conducted to explore the formation of structures using chemical vapor deposition (CVD) processes to simultaneously seal etch hole and prevent adhesion owing to polysilicon film vibration.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.4
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• pp.327-331
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• 2008

An in-line wet etch/cleaning system was established for the research and development in wet etch process as a formation of electrode such as metal or transparent conductive oxide layer. A reverse moving system was equipped in the in-line wet etch/cleaning system for the alternating motion of glass substrate in a wet etch bath of the system. Therefore, it was possible for the glass substrate to be moved back and forth and it was possible to reduce the size of the system by using the reversing moving system. For the effect of the alternating motion of substrate on the etch rate in the in-line wet etch bath, indium tin oxide(ITO) patterns were obtained through wet etch process in the in-line system in which the substrate was moved back and forth. From the CD(critical dimension) skews resulted from the ADI CD and ACI CD of the ITO patterns, it was concluded that the alternating motion of glass substrate are possible to be applied to the mass production of wet etch process.