• Journal of the Speleological Society of Korea
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• no.77
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• pp.21-30
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• 2007

Photo-lithography lies in the middle of the wafer fabrication process. It is often considered as the most critical step in the IC process. We use a mask in exposure steps of the photo-lithography. Typically, 20 to 25 different levels of masks are required to complete an IC device. That means, if a photo process can be developed with the use of only one photo mask, we can reduce more process cost. To satisfy this, we plan to develop an alternative photo mask. For this reason, we chose to use a LCD. We expect to develop a LCD panel that can be changed by electrical control. This is the main idea about the adjustive photo mask. The Photo mask made of LCD panel will replace the former one.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.76-76
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• 2007

Several kinds of photo-chromic polymers containing push-pull structure were synthesized and investigated on optical patterning by photo-induced surface relief gratings (SRG) technique. The azobenzene segment was introduced as a functional group for a photo-triggered tran-cis isomerization. Consequently, we have fabricated micro-size regular pattern by one-step process without photo-mask.

• Korean Journal of Optics and Photonics
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• v.18 no.5
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• pp.303-308
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• 2007

We report here on the application of a digital holographic microscope as a metrology tool for the inspection and the micro-topography reconstruction of different micro-structures of phase shift photo-mask (PSM). The lithography by phase shift photo-mask uses the interference and the pattern of the PSM is not imaged by general optical microscope. The technique allows us to obtain digitally a high-fidelity surface topography description of the phase shift photo-mask with only one hologram image acquisition, allowing us to have relatively simple and compact set-ups able to give quantitative information of PSM.

• Journal of the Semiconductor & Display Technology
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• v.19 no.3
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• pp.12-18
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• 2020

In semiconductor manufacturing, defect detection is critical to maintain high yield. Currently, computer vision systems used in semiconductor photo lithography still have adopt to digital image processing algorithm, which often occur inspection faults due to sensitivity to external environment. Thus, we intend to handle this problem by means of using Mask R-CNN instead of digital image processing algorithm. Additionally, Mask R-CNN can be trained with image dataset pre-processed by means of the specific designed digital image filter to extract the enhanced feature map of Convolutional Neural Network (CNN). Our approach converged advantage of digital image processing and instance segmentation with deep learning yields more efficient semiconductor photo lithography inspection system than conventional system.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.3
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• pp.15-20
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• 1997

This paper presents the experimental study of the non-contact temperature measurement for the shadow mask of cathode ray tube using InSb sensor. At present, High resolution of CRT(Cathode Ray Tube) is needed broadly; therefore, the measurement of temperature distribution of shadow mask in CRT during operation is important to analyze the thermal deformation of shadow mask. Most of the studies could not measure the temperature distribution of shadow mask precisely. We studied the temperature dis- tribution of shadow mask using InSb photo sensor for 17" cathode ray tube (CRT). Experiments using ther- mocouple are performed to validate the results of non-contact measurement. The results agree well with those results of non-contact method using InSb sensor.nsor.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1175-1178
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• 2005

Brittle materials, especially single-crystal silicon wafer, are widely used for sensors, IC industry, and MEMS applications. e general machining process of crack easy materials is by chemical agents, but it is hazardous and time consuming. Also, it is difficult to get high aspect ratio micro structure. As an alternative tool, an AJM(Abrasive jet machining) is promising method in terms of high aspect ratio and production cost. In this study, to get more precise detail compared to general AJM, photo polymer mask, SU-8, used in photolithography was applied in AJM. Process parameters such as abrasive diameter, air pressure, nozzle diameter, flow rate of abrasive in AJM and a variety of conditions in spin coating were decided. Finally, micro channel and mixer was fabricated to see the efficiency of the AJM with photo polymer mask.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.37.2-37.2
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• 2011

반도체공정에서 Photo-lithography는 특정 광원을 사용하여 구현하고자 하는 패턴을 기판상에 형성하는 기술이다. 이러한 Photo-lithography 공정에서는 패턴이 형성되어 있는 마스크가 핵심적인 역할을 하며 반도체소자의 전체적인 성능을 결정한다. 이에 따라 Photo-lithography용 마스크에 사용되는 Blank 마스크는 Defect의 최소화 및 우수한 평탄도 등의 조건들이 요구되고 있다. 이러한 Blank 마스크 재료로 광원을 효율적으로 투과시키는 성질이 우수하고 다른 재료에 비해 열팽창계수가 작은 석영기판이 사용되고 있다. 석영 기반의 마스크는 UV Lithography에서 주로 사용되고 있으며 그 밖에 UV-NIL (Nano Imrpint Lithography), EUVL (Extreme Ultra Violet Lithography) 등에도 이용되고 있다. 석영기판을 가공하여 Blank 마스크로 제작하기 위해 석영기판의 Lapping/Polishing 등이 핵심기술이며 현재 일본에서 전량 수입에 의존하고 있어, 이에 대한 연구의 필요성이 절실한 상황이다. 본 연구에서는 Blank 마스크제작을 위한 석영기판의 Polishing 공정에 사용되는 Ceria Slurry의 특성 연구 및 이에 따른 연마평가를 실시하였으며 첨가제의 조건에 따른 pH/Viscosity/Stability 등의 물리적인 특성을 관찰하여 석영기판 Polishing에 효율적인 Ceria slurry의 최적조건을 도출했다. 또한, 조건에 따른 Slurry의 정확한 분석을 위해 Zeta Potential Analyzer를 이용하여 연마입자의 크기 및 Zeta Potential에 대한 평가를 실시한 후 연마제와 석영기판의 Interaction force를 측정하였다. 상기 실험에 의해 얻어진 최적화된 연마 공정 조건하에서 Ceria slurry를 사용하여 연마평가를 실시함으로써 Removal Rate/Roughness 등의 결과를 관찰하였다. 본 연구를 통해 반도체 photo mask 제작을 위한 Ceria slurry의 주요특성을 파악하고 석영기판의 Polishing에 효율적인 조건을 도출함으로써 Lithography 마스크를 효율적으로 제작할 수 있을 것으로 예상된다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.503-507
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• 2002

Mask manufacturing is a high COC and COO process in developing of semiconductor devices, because of the mass production tool with high resolution. Direct writing has been thought to be one of the patterning method to cope with development or small-lot production of the device. This study focused on the development of the direct, mastless patterning process using stereolithography tool for the easy and convenient application to micro and miso scale products. Experiments are utilized by three dimensional CAD/CAM as a mask and photo-curable resin as a photo-resist in a conventional stereo-lithography apparatus. Results show that the resolution of the pattern was achieved about 300 micron because of complexity of SLA apparatus settings, inspite of 100 micro of inherent resolution. This paper concludes that photo resist and laser spot diameter should be adjusted to get finer patterns and the proposed method is significantly feasible to mastless and low cost patterning with micro and miso scale.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1993-1998
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• 2011

Semiconductor industry needs to have fine patterns in order to fabricate the high density integrated circuit. For nano-scale patterns, hard-mask is used to multi-layer structure which is formed by CVD (chemical vaporized deposition) process. In this work, we prepared single-layer hard-mask by using organic-inorganic hybrid polymer for spin-on process. The inorganic part of hard-mask was much easier etching than photo resist layer. Beside, the organic part of hard-mask was much harder etching than substrate layer. We characterized the optical and morphological properties to the hard mask films using organic-inorganic hybrid polymer, and then etch rate of photo resist layer and hard-mask film were compared. The hybrid polymer prepared from organic and inorganic materials was found to be useful hard-mask film to form the nano-patterns.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.1 s.190
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• pp.71-78
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• 2007

Abrasive jet machining (AJM) has been traditionally used for removing rusts or paints. Nowadays, this is promising technology for micro bulk machining where brittle substrate materials are used. In order to get accurate details, masks such as metal, polymer or elastomer is inevitable. Among them, photo polymer which is sensitive to the light has been attractive for it's high accuracy using photolithography. In this research, SU-8 as a photo polymer is used since it is adequate for making thick mask. So, this paper describes how to make AJM masks using SU-8 with a photolithography process, and investigates the characteristics of SU-8 masks during AJM process. Also, an example of fabrication using AJM was shown.