디지털 홀로그래피를 이용한 포토리소그래피 공정 제품 패터닝의 폭과 단차 측정

신주엽(Ju Yeop Shin),강성훈(Sung Hoon Kang),마혜준(Hye Joon Ma),권익환(Ik Hwan Kwon),양승필(Seung Pil Yang),정현철(Hyun Chul Jung),홍정기(Chung Ki Hong),김경석(Kyeong Suk Kim) 한국비파괴검사학회 2016 한국비파괴검사학회지 Vol.36 No.1

반도체 산업은 우리나라 주력산업중 하나로 매년 꾸준한 성장세를 보이며 지속적인 성장을 하고 있다. 이러한 반도체 산업에서의 중요한 기술은 소자의 고 집적화이다. 이는 면적당 메모리 용량을 증가시키는 것으로 핵심역할을 하는 것이 바로 포토리소그래피 기술이다. 포토리소그래피란 마스크의 표면에 빛을 쬐어 생기는 그림자를 웨이퍼 상에 인쇄하는 기술이며 반도체 제조공정에서의 가장 중요한 공정이다. 이러한 공정을 통해 나온 패터닝을 분석 시에 폭과 단차의 균일성을 측정한다. 이에 따라 본 논문은 포토리소그래피 공정이 적용된 시험편 패터닝에 폭과 판 사이와의 단차를 투과형 디지털 홀로그래피를 구성하여 측정하고자 한다. 투과형 디지털 홀로그래피 간섭계를 구성하고 시험편에 임의의 9포인트를 설정하여 각 포인트를 측정하고 상용장비인 SEM (scanning electron microscopy)과 alpha step으로 측정한 결과와 비교하고자 한다. 투과형 디지털 홀로그래피는 측정시간이 타 기법에 비에 짧다는 장점과 배율렌즈를 사용하기 때문에 저 배율에서 고 배율로 변경하여 측정할 수 있는 장점을 가지고 있다. 실험 결과로부터 투과형 디지털 홀로그래피가 포토리소그래피가 적용된 패터닝 측정에 유용한 기술임을 확인할 수 있었다. The semiconductor industry is one of the key industries of Korea, which has continued growing at a steady annual growth rate. Important technology for the semiconductor industry is high integration of devices. This is to increase the memory capacity for unit area, of which key is photolithography. The photolithography refers to a technique for printing the shadow of light lit on the mask surface on to wafer, which is the most important process in a semiconductor manufacturing process. In this study, the width and step-height of wafers patterned through this process were measured to ensure uniformity. The widths and inter-plate heights of the specimens patterned using photolithography were measured using transmissive digital holography. A transmissive digital holographic interferometer was configured, and nine arbitrary points were set on the specimens as measured points. The measurement of each point was compared with the measurements performed using a commercial device called scanning electron microscope (SEM) and Alpha Step. Transmission digital holography requires a short measurement time, which is an advantage compared to other techniques. Furthermore, it uses magnification lenses, allowing the flexibility of changing between high and low magnifications. The test results confirmed that transmissive digital holography is a useful technique for measuring patterns printed using photolithography.

Measurement of the Wear Amount of WC-coated Excavator Spacer using the PTA Process to Improve Wear Resistance by Using Reflective Digital Holography

Ju-Yeop Shin(신주엽),Hyeong-Jong Lim(임형종),Hang-Seo Lee(이항서),Han-Sub Kim(김한섭),Hyun-Chul Jung(정현철),Kyeong-suk Kim(김경석) 한국기계가공학회 2020 한국기계가공학회지 Vol.19 No.1

The spacer, which is located between the bucket and the arm of an excavator, has a role in preventing damage to the excavator arm during excavation work. When the durability of the spacer is increased, the lifetime of the arm can be extended and the processing costs can be reduced. To increase the durability of the spacer, tungsten carbide (WC) coating was applied on the surface of a spacer using the plasma transferred arc (PTA) process. The confirm the durability, a wear test using a pin-on disk type of wear testing machine was done under the given conditions and the wear amount on the surface of a tested specimen was measured using reflective digital holography. The results were compared with that of ALPHA-STEP.

스퍼터링 공법으로 제작한 ITO 박막의 디지털 홀로그래피를 이용한 단차에 대한 측정

정현일(Hyun Il Jung),신주엽(Ju Yeop Shin),박종현(Jong Hyun Park),정현철(Hyunchul Jung),김경석(Kyeong-suk Kim) 한국기계가공학회 2021 한국기계가공학회지 Vol.20 No.9

Indium tin oxide (ITO) transparent electrodes, which are used to manufacture organic light-emitting diodes, are used in light-emitting surface electrodes of display EL panels such as cell phones and TVs, liquid crystal panels, transparent switches, and plane heating elements. ITO is a major component that consists of indium and tin and is advantageous in terms of obtaining sheet resistance and light transmittance in a thin film. However, the optical performance of devices decreases with an increase in its thickness. A digital holography system was constructed and measured for the step measurement of the ITO thin film, and the reliability of the technique was verified by comparing the FE-SEM measurement results. The error rate of the step difference measurement was within ±5%. This result demonstrated that this technique is useful for applications in advanced MEMS and NEMS industrial fields.

반사형 디지털 홀로그래피를 이용한 허니콤 구조의 회로선 폭 측정

정현일(Hyunil Jung),신주엽(Ju-Yeop Shin),이설희(SeolHee Yi),권익환(Ik-Hwan Kwon),정현철(Hyunchul Jung),김경석(Kyeong-Suk Kim) 한국비파괴검사학회 2017 한국비파괴검사학회지 Vol.37 No.3

반도체 제작 시 포토리소그래피 공정은 설계한 전기회로패턴을 기판 위에 옮기는 공정이다. 기판에 가공된 패턴이 설계한 전기회로와 정확히 일치하게 전사되었는지의 여부는 반도체 고집적화 연구에서 매우 중요하며, 주로 AFM, FE-SEM, Alpha Step, CIRCLTM Suite 등의 장비를 이용하여 검사한다. 본 논문에서는 디지털 홀로그래피를 이용한 검사 방법을 제시하였다. 이를 위해 포토리소그래피 공정으로 허니컴 패턴이 제작된 반사형 시험대상체 상에 임의로 9곳의 측정점을 지정하였다. 반사형 디지털 홀로그래피를 이용하여 허니컴 패턴으로 제작된 회로의 선 폭을 측정하고, 그 결과로부터 회로가 설계한대로 정확히 전사되었는지 여부를 확인하였다. 반사형 디지털 홀로그래피로 측정한 결과값의 신뢰성을 확인하기 위하여 통상적으로 쓰이는 검사장치인 AFM과 FE-SEM으로 측정하여 그 결과를 비교, 검증하였다. During semiconductor fabrication, the photolithography process is a transfer printing process used to replicate the designed electric circuit pattern onto a wafer or circuit board. For studies related to high integration of semiconductors, it is very important to confirm whether the printed pattern is fabricated with complete fidelity. AFM, FE-SEM, Alpha Step, and CIRCLTM Suite are typically used systems for inspecting the printed pattern. In this paper, an inspection method using digital holography is proposed. For this purpose, nine measuring points on a reflective object, which the honeycomb pattern in the photolithography process was printed on, were selected arbitrarily. The line width of the honeycomb pattern printed on the wafer was measured using the reflection type of the digital holography. Subsequently, it was confirmed whether the pattern was correctly printed or not. In order to verify the reliability of the reflection type of the digital holography, the results of the digital holography were compared with those of AFM and FE-SEM, and it was confirmed that the deviation from AFM and FE-SEM was within 3% and 0.5%, respectively.

불멸화된 일차 간세포를 이용한 C형 간염바이러스의 in vitro 배양

최정은 ( Jung Eun Choi ),허원희 ( Won Hee Hur ),신주엽 ( Ju Yeop Shin ),박련숙 ( Lian Shu Piao ),윤승규 ( Seung Kew Yoon ) 대한소화기학회 2008 대한소화기학회지 Vol.52 No.3

Background/Aims: It is essential to develop an in vitro culture model of primary hepatocytes for the study of hepatocellular function and the pathogenesis of hepatitis C virus (HCV) infection. In this study, we have established the immortalized primary human hepatocyte (IPHH) and performed in vitro culture of HCV derived from human patient. Methods: Primary human hepatocytes were isolated from surgically resected liver tissue and then were immortalized by transfection with the SV40 large T antigen. The characterization of the IPHH during culture was analyzed by immunocytochemistry, RT-PCR, Western blot, ELISA, and soft agar assay. Next, sera and/or liver tissue homogenates from surgically resected liver tissues of patients with HCV infection were inoculated for the culture of HCV in IPHH. After HCV RNA extraction from IPHH and culture media, positive or negative stranded HCV RNA was examined by specific nest RT-PCR. Results: IPHH expressed liver-associated proteins but did not express alpha-fetoprotein. Also IPHH showed ammonia removal activity. With regard to its malignant potential, colony formation in soft agar assay was not observed. Next, positive and negative stranded HCV RNAs in IPHH infected with patient`s sera plus liver tissue homogenates were clearly detected whereas those in IPHH infected with only patient`s sera were not detected. Conclusions: These results demonstrated the phenotypic characteristics of IPHH and the feasibility in vitro culture system of HCV infected human samples. This system might be useful for study of pathogenesis of HCV infection or hepatocyte-based applications. (Korean J Gastroenterol 2008;52:150-160)

반사형 디지털 홀로그래피를 이용한 Molybdenum 박막의 손상 측정

김경석(Kyeong-Suk Kim),정현일(Hyun-Il Jung),신주엽(Ju-Yeop Shin),마혜준(Hye-Joon Ma),권익환(Ik-Hwan Kwon),양승필(Seung-Pill Yang),홍정기(Chung-Ki Hong),정현철(Hyun-Chul Jung) 한국비파괴검사학회 2015 한국비파괴검사학회지 Vol.35 No.2

전자제품에 필수적으로 사용되는 전자회로의 제작 시, 반도체 위에 증착하는 박막의 산화를 방지하기 위하여 molybdenum을 증착한다. Molybdenum 박막 증착 시 표면의 particle 또는 dust의 존재는 밀착력 감소 및 성능 저하, 수명 단축, 안전도 저하를 유발한다. 본 논문에서는 particle의 유무에 따른 molybdenum 박막 증착부의 변화를 보기 위하여, 두 가지 glass substrate를 대상으로 손상 측정 실험을 하였다. Sputtering 증착 기법으로 molybdenum이 glass substrate에 직접 코팅이 되는 clean과 dirty 두 종류의 molybdenum 박막을 제작하고, 손상 측정을 위해 반사형 디지털 홀로그래피를 구성하였다. 반사형 디지털 홀로그래피는 간섭계의 구성이 손쉽고 다양한 배율렌즈를 적용하여 측정영역에 다양성을 줄 수 있으며, 측정시간이 타 기법에 비해 짧다는 장점을 가진다. 실험 결과로부터 반사형 디지털 홀로그래피가 박막의 손상 및 결함 측정에 유용한 기술임을 확인하였다. In the fabrication of electronic circuits used in electronic products, molybdenum thin films are deposited on semiconductors to prevent oxidation. During the deposition, the presence of a particle or dust at the interface between the thin film and substrate causes the decrease of adhesion, performance, and life cycle. In this study, a damage measurement targeting two kinds of glass substrate, with and without particles, was performed in order to measure the change in the molybdenum thin film deposition area in the presence of a particle. Clean and dirty molybdenum thin film specimens were fabricated and directly deposited on a substrate using the sputtering method, and a reflection-type digital holographic interferometer was configured for measuring the damage. Reflection-type digital holography has several advantages; e.g., the configuration of the interferometer is simple, the measurement range can be varied depending on the magnification of a microscopic lens, and the measuring time is short. The results confirm that reflection-type digital holography is useful for the measurement of the damage and defects of thin films.