• Journal of the Semiconductor & Display Technology
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• v.20 no.2
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• pp.34-42
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• 2021

Recent cleaning technologies of mask in extremely ultraviolet semiconductor processes were reviewed, focused on newly developed issues such as particle size determination or hydrocarbon and tin contaminations. In detail, critical particle size was defined and proposed for mask cleaning where nanosized particles and its various shapes would result in surface atomic ratio increase vigorously. A new cleaning model also was proposed with amphoteric behavior of electrolytically ionized water which had already shown excellent particle removing efficiency. Having its non-equilibrium and amphoteric properties, electrolyzed ion water seemed to oxidize contaminant surface selectively in nano-scale and then to lift up oxidized ones from mask surface very effectively. This assumption should be further investigated in future in junction with hydrogen bonding and cluster of water molecules.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2004.05a
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• pp.129-131
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• 2004

극자외선 리소그래피(EUV lithography) 기술은 50nm 이하의 선폭을 가지는 차세대 소자 제작에 있어서 선도적인 기술 중 하나이다. EUVL 에서 필수적인 요소중의 하나가 mirror 로 사용되는 blank mask 이다. Blank mask 에 있어서 가장 중요한 요소는 반사도이다. 이 blank mask 는 Si substrate 위에 반사를 위한 Mo/Si pair 가 40pair 이상 적층되어있다. Blank mask 는 매우 청결해야한다. 만약 결함이 있다면 blank mask 에는 치명적이다 결함은 blank mask 에 있어서 반사도를 떨어뜨리는 주 요소이기 때문이다. 그 결함에는 amplitude defect 과 phase defect 이 있다. FIB 에서는 amplitude defect 을 수정하는 것이 가능하다. 우리는 FIB 를 이용하여 mage mode, spot mode, bar rotation mode 를 사용하여 amplitude defect을 수정하였다. 그리고, 그 결과 효과적으로 amplitude defect을 수정하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.1
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• pp.61-69
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• 2014

With the extreme ultraviolet (EUV) lithography, the performance limit of chemically amplified resists has recently been extended to 16- and 11-nm nodes. However, the line edge roughness (LER) and the line width roughness (LWR) are not reduced automatically with this performance extension. In this paper, to investigate the impacts of the EUVL mask and the EUVL exposure process on LER, EUVL is modeled using multilayer-thin-film theory for the mask structure and the Monte Carlo (MC) method for the exposure process. Simulation results demonstrate how LERs of the mask transfer to the resist and the exposure process develops the resist LERs.

• Journal of the Semiconductor & Display Technology
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• v.14 no.3
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• pp.1-5
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• 2015

In photolithography process, resolution enhancement techniques such as optical proximity correction (OPC) and phase shift mask (PSM) have been applied to improve resolution. Especially, sub-resolution assist feature (SRAF) is one of the most important OPC to enhance image quality including depth of focus (DOF). However, imaging performance of the mask could be varied with the diffraction order amplitude changed by inserting SRAF. Therefore, in this study, we investigated the imaging properties and process margin of attenuated PSM with SRAF. Reflectivities of attenuated PSMs at 13.5 nm were 3, 6, 9% and simulation was performed by $PROLITH^{TM}$. As a result, aerial image properties and DOF as well as diffraction efficiency were improved by increasing the reflectivity of attenuated PSM. Additionally, printed critical dimension variations depending on SRAF width and space error were also reduced for attenuated PSM with high reflectivity. However, SRAF could be printed when reflectivity of attenuated PSM is high enough. In conclusion, optimization of reflectivity of attenuated PSM and SRAF to prevent side-lobe from being printed is needed to be considered.

• Journal of the Semiconductor & Display Technology
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• v.15 no.2
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• pp.32-37
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• 2016

Sidewall angle (SWA) of an absorber stack in extreme ultraviolet lithography mask is considered to be $90^{\circ}$ ideally, however, it is difficult to obtain $90^{\circ}$ SWA because absorber profile is changed by complicated etching process. As the imaging performance of the mask can be varied with this SWA of the absorber stack, more complicated optical proximity correction is required to compensate for the variation of imaging performance. In this study, phase shift mask (PSM) is suggested to reduce the variation of imaging performance due to SWA change by modifying mask material and structure. Variations of imaging performance and lithography process margin depending on SWA were evaluated through aerial image and developed resist simulations to confirm the advantages of PSM over the binary intensity mask (BIM). The results show that the variations of normalized image log slope and critical dimension bias depending on SWA are reduced with PSM compared to BIM. Process margin for exposure dose and focus was also improved with PSM.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.269-274
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• 1999

As the semiconductor industry enters the next century, we are facing to the technological changes and challenges. Optical lithography has driven by the miniaturisation of semiconductor devices and has been accompanied by an increase in wafer productivity and performance through the reduction of the IC image geometries. In the last decade, DRAM(Dynamic Random Access Memories) have been quadrupoling in level of integration every two years. Korean chip makers have been produced the memory devices, mainly DRAM, which are the driving force of IC＇s(Integrated Circuits) development and are the technology indicator for advanced manufacturing. Therefore, Korean chip makers have an important position to predict and lead the patterning technology. In this paper, we will be discussed the limitations of the optical lithography, such as KrF and ArF. And, post optical lithography technology, such as E-beam lithography, EUV and E-beam Projection Lithography shall be introduced.

• Proceedings of the Korean Vacuum Society Conference
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• 2008.08a
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• pp.291-291
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• 2008

• Journal of Powder Materials
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• v.30 no.2
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• pp.156-168
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• 2023

The semiconductor industry faces physical limitations due to its top-down manufacturing processes. High cost of EUV equipment, time loss during tens or hundreds of photolithography steps, overlay, etch process errors, and contamination issues owing to photolithography still exist and may become more serious with the miniaturization of semiconductor devices. Therefore, a bottom-up approach is required to overcome these issues. The key technology that enables bottom-up semiconductor manufacturing is area-selective atomic layer deposition (ASALD). Here, various ASALD processes for elemental metals, such as Co, Cu, Ir, Ni, Pt, and Ru, are reviewed. Surface treatments using chemical species, such as self-assembled monolayers and small-molecule inhibitors, to control the hydrophilicity of the surface have been introduced. Finally, we discuss the future applications of metal ASALD processes.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.59-59
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• 2012

Vacuum pumping remains central to the performance and economy of many manufacturing processes, scientific instruments and scientific research. More vacuum is being used in many of the latest or leading edge manufacturing processes: Current examples include 3D semiconductor devices, EUV lithography, 450 mm silicon wafers, AMOLED displays, LEDs, Lithium-ion batteries and steel degassing. In other applications, vacuum pumping technology developments have led to much lower product costs which for example have enabled mass spectrometers to become a ubiquitous tool is life science research. Vacuum pumps have continuously evolved during the past 100 years of vacuum-based industrial processing but remain a key component which is often on the critical path of process and product improvements. This is especially so in the growing number of applications where the pumps are highly stressed. This presentation outlines significant developments in vacuum that have brought about this progress. The likely course of continued improvements is discussed in terms of increased performance and reliability, robust by-product handling, better cost efficiency and reduced environmental impact especially power consumption.

• Proceedings of the Korean Vacuum Society Conference
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• 2008.02a
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• pp.177-177
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• 2008