회전형 CMP장비의 속도 및 마찰력 분포 해석

김형재(Hyoungjae Kim),정해도(Haedo Jeong),이응숙(Eungsug Lee),신영재(Youngjae Shin) Korean Society for Precision Engineering 2003 한국정밀공학회지 Vol.20 No.5

다중 감시장치를 이용한 박막의 평탄화 연구

김형재(Hyoungjae Kim),정해도(Haedo Jeong) 한국기계가공학회 2006 한국기계가공학회 춘추계학술대회 논문집 Vol.2006 No.-

In this paper, three different sensors were used to measure multi-scale phenomena in chemical mechanical planarization. A piezoelectricforce sensor, Hall effect sensor and acoustic emission sensor (AE) were installed in CMP equipment and the signals were measured simultaneously during the polishing process. The results showed that the sensors measuring frictional behaviour, such as the Hall effect sensor and force transducer, produced a clear end point signal in the case of the friction characteristics are distinguishable for each material. Also, if there is difference in hardness between materials, then a sharp end point signal is detected with the AE sensor even though the friction characteristic is similar between the two materials. Therefore, using multi-sensors having different bandwidths is complementary for not only process monitoring but also end point detection.

[재료부문] 인스트루먼트 패널용 표피재 특성 평가

김형재(Hyoungjae Kim),김성호(Seongho Kim),김대업(Daeup Kim) 한국자동차공학회 2001 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2001 No.11_2

The requirement of materials is being changed according to change of design for automotive instrument panel. Passenger air bag is being changed from visible type to invisible type. And users are demanding more soft feel of skin materials of instrument panel. The vacuum forming process is used in the preparation of an instrument panel by PVC/ABS. Currently most of the instrument panels are formed by powder slush molding by PVC. Previous materials -PVC/ABS. PVC- don't meet these requirements. TPU (Thermoplastic Urethane) was developed for satisfying user demand in interior mm. The comparative evaluation of TPU and other materials shows that TPU can reduce production weight, meet requirement of deploy test at low temperature. and pass perfectly heat aging test. Besides, it is recyclable. It is concluded that TPU can be applied to the invisible passenger air bag system.

[정밀가공 부문] 10 nm급 반도체 디바이스구현을 위한 CMP기술

김형재(Hyoungjae Kim) Korean Society for Precision Engineering 2021 한국정밀공학회 학술발표대회 논문집 Vol.2021 No.11월

현재의 추세로 디지털세상이 발전한다면 사물인터넷(Internet of Things)의 증가, 모바일 기기의 발달 그리고 기기간의 연결(Connected Devices) 가속화로 2025년에는 매일 약 4.6억 Tb의 데이터가 생성될 것으로 예측되며, 이러한 데이터 기반 사회의 뿌리에는 끊임없이 진화하는 반도체 디바이스의 제조기술 발전이 뒷받침 하고 있다. 역사적으로 오랜 기간 동안 광학부품의 초정밀 연마기술이었던 화학기계적연마(Chemical Mechanical Polishing, CMP)공정은 1983년 IBM에서 반도체 소자의 단차 극복을 위해 최초로 반도체 공정에 적용되었다. 이후 매년 지수적인 집적도 증가(Moore’s Law)에 맞추어 최소선폭은 감소하고, 이러한 기술적 장벽에 대응하기 위해 CMP는 연마라는 본질적인 기술바탕 위에 완전히 새로운 기술적 요구를 가진 평탄화(Chemical Mechanical Planarization)라는 기술 특성을 끊임없이 발전시켜 왔다. 최초 절연막 평탄화 공정에서 시작하여 공정적인 측면에서는 수직배선, 수평배선, 소자분리, 고단차 극복 등의 공정으로 확대되었으며, 이러한 공정을 구현하기 위하여 배선영역에서의 디싱(Dishing)결함, 고밀도 영역에서의 에로젼(Erosion) 결함, 위치별 패턴밀도 차이에 의해 발생하는 평탄도 오차, 10x nm급의 소자에서 발생하는 나노토포그라피 기인 평탄도 오차 등을 극복하기 위하여 가공종점 검출기술과 슬러리 성능의 고도화, 패드의 물성변화, 장비의 발전, 공정조건의 다변화라는 기술적 발전을 이루어 왔다. 다른 한편으로, 재료적인 측면에서 실리콘산화막, 질화실리콘, a-Si, Low-k 및 High-k산화막, 알루미늄, 구리, 텅스텐, Ta, TaN, Ti, TiN, 코발트, 루테늄, 폴리머 등으로 연마대상물질이 다양화 되었다. 이러한 재료의 다양화와 여러 재료가 동시에 드러나면서 연마가 이루어지는 복합적인 상황은 상대적으로 개발주기가 긴 패드에 기술변화를 부여하기 보다 패드변수를 고정하고 화학적 제어의 범위가 크고 다양한 접근이 가능한 슬러리에서의 기술 변화를 더욱 가속화 시켰다. 연마재 측면에서는 퓸드 및 콜로이달 실리카, 폴리머 연마재, 표면 모폴로지 제어입자, 콜로이달 세륨옥사이드, 망간옥사이드 등의 다양한 입자가 평가되고 적용되었으며, 용액측면에서는 pH제어제, 계면활성제, 산화제, 촉매, 착화제, 킬레이트제 등의 다변화를 불러왔다. 또한 웨이퍼 단위로 진행되는 공정 특성상 웨이퍼전면에서의 연마균일도확보(WIWNU)와 가장자리 영역(Edge Exclusion)에서의 수율증가를 위하여 10구역이 넘는 멤브레인 압력 제어시스템과 리테이너링 구조의 발달, 그리고 이들과 웨이퍼 압력프로파일 실시간 제어를 위한 웨이퍼 표면 모니터링 기술의 발전을 가속화 시켜 분당 100미터가 넘는 속도로 100 μm수준의 굴곡을 가진 패드위를 달리는 물리적 외란 조건하에서 웨이퍼 표면 박막에서 일어나는 단 수십개의 원자층 변화도 감지할 수 있기에 이르렀다. 마지막으로 소자의 크기가 10x nm급에서 10 nm 이하 영역으로 미세화되면서 소자가 작아지는 만큼 킬러결함의 상대적 비율도 증가하게 되었으며, 연마재로 연마함에도 불구하고 스크래치를 남기지 않도록 입자 크기제어, 반응 생성층의 형성과 제거의 평형상태 유지해야 하며, 연마후 잔류 연마입자를 남기지 않기 위해 연마 후 초청정 세정(Post CMP Cleaning)기술은 CMP기술 분야에서 어느 때 보다 중요한 핵심기술로 자리매김 하고 있다.

CMP 결과에 영향을 미치는 마찰 특성에 관한 연구

박범영,이현섭,김형재,서헌덕,김구연,정해도,Park, Boumyoung,Lee, Hyunseop,Kim, Hyoungjae,Seo, Heondeok,Kim, Gooyoun,Jeong, Haedo 한국전기전자재료학회 2004 전기전자재료학회논문지 Vol.17 No.10

Chemical mechanical polishing (CMP) process was studied in terms of tribology in this paper. CMP performed by the down force and the relative motion of pad and wafer with slurry is typically tribological system composed of friction, wear and lubrication. The piezoelectric quartz sensor for friction force measurement was installed and the friction force was detected during CMP process. Various friction signals were attained and analyzed with the kind of pad, abrasive and abrasive concentration. As a result of experiment, the lubrication regime is classified with ηv/p(η, v and p; the viscosity, relative velocity and pressure). The characteristics of friction and material removal mechanism is also different as a function of the kind of abrasive and the abrasive concentration in slurry. Especially, the material removal per unit distance is directly proportional to the friction force and the non~uniformity has relation to the coefficient of friction.

CMP 공정중 패드 표면의 온도분포에 관한 연구

정영석(Youngseok Jeong),김형재(Hyoungjae Kim),정해도(Haedo Jeong) 대한기계학회 2003 대한기계학회 춘추학술대회 Vol.2003 No.4

The friction heat generated by the CMP process hasinfluence on removal rate and WIWNU(Within Wafer Non-Uniformity). Therefore, the object of this study in to find the distribution of temperature on pad surface during CMP process. To do this, the authors analyse the kinematics of CMP equipment to verify the sources of friction heat and compare the analysis result with the experimental results. Through the analysis and experiment conducted in this paper, we can predict the distribution of polishing temperature across the pad surface. Furthermore the result could help to predict the process conditions which could enhance the polishing results, such as WIWNU and removal rate of thin film to achieve more effcient process.

염화칼륨 농도에 따른 사파이어 기판 CMP에 관한 연구

박철진(Chuljin Park),김형재(Hyoungjae Kim),정해도(Haedo Jeong) 한국트라이볼로지학회 2017 한국윤활학회지(윤활학회지) Vol.33 No.5

Chemical Mechanical Polishing of chemically stable sapphire substrates is dominantly affected by the mechanical processing of abrasives, in terms of the material removal rate. In this study, we investigated the effect of electrostatic force between the abrasives and substrate, on the polishing. If potassium chloride (KCl) is added to slurry, water molecules are decomposed into H+ and OH− ions, and the amount of ions in the slurry changes. The zeta potential of the abrasives decreases with an increase in the amount of H+ ions in the stern layer; consequently, the electrostatic force between the abrasives and substrate decreases. The change in zeta potential of abrasives in the slurry is affected by the slurry pH. In acidic zones, the amount of ions bound to the abrasives increases if the amount of H+ ions is increased by adding KCl. However, in basic zones, there is no change in the corresponding amount. In acidic zones, zeta potential decreases as molar concentration of potassium increases; however, it does not change significantly in basic zones. The removal rate tends to decrease with increase in molar amount of potassium in acidic zones, where zeta potential changes significantly. However, in basic zones, the removal rate does not change with zeta potential. The tendencies of zeta potential and that of the frictional force generated during polishing show strong correlation. Through experiments, it is confirmed that the contact probability of abrasives changes according to the electrostatic force generated between the abrasives and substrate, and variation in removal rate.

CMP 공정에서 나노 연마입자에 의한 박막표면 스크래치 발생 원인 규명에 관한 연구

박범영(Boumyoung Park),김형재(Hyoungjae Kim),김성렬(Sungryul Kim),류호연(Hoyeun Ryu) 한국정밀공학회 2010 한국정밀공학회 학술발표대회 논문집 Vol.2010 No.5월

Self-conditioning 고정입자패드를 이용한 CMP

박범영,이현섭,박기현,서헌덕,정해도,김호윤,김형재,Park, Boumyoung,Lee, Hyunseop,Park, Kihyun,Seo, Heondeok,Jeong, Haedo,Kim, Hoyoun,Kim, Hyoungjae 한국전기전자재료학회 2005 전기전자재료학회논문지 Vol.18 No.4

Chemical mechanical polishing(CMP) process is essential technology to be applied to manufacturing the dielectric layer and metal line in semiconductor devices. It has been known that overpolishing in CMP depends on pattern selectivity as a function of density and pitch, and use of fixed abrasive pad(FAP) is one method which can improve the pattern selectivity. Thus, dishing & erosion defects can be reduced. This paper introduces the manufacturing technique of FAP using hydrophilic polymers with swelling characteristic in water and explains the self-conditioning phenomenon. When applied to tungsten blanket wafers, the FAP resulted in appropriate performance in point of uniformity, material selectivity and roughness. Especially, reduced dishing and erosion was observed in CMP of tungsten pattern wafer with the proposed FAP.

사파이어 웨이퍼 DMP에서 마찰력 모니터링을 통한 재료 제거 특성에 관한 연구

조원석(Wonseok Jo),이상직(Sangjik Lee),김형재(Hyoungjae Kim),이태경(Taekyung Lee),이성범(Seongbeom Lee) 한국트라이볼로지학회 2016 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.32 No.2

Sapphire has a high hardness and strength and chemical stability as a superior material. It is used mainly as a material for a semiconductor as well as LED. Recently, the cover glass industry used by a sapphire is getting a lot of attention. The sapphire substrate is manufactured through ingot sawing, lapping, diamond mechanical polishing (DMP) and chemical mechanical polishing (CMP) process. DMP is an important process to ensure the surface quality of several nm for CMP process as well as to determine the final form accuracy of the substrate. In DMP process, the material removal is achieved by using the mechanical energy of the relative motion to each other in the state that the diamond slurry is disposed between the sapphire substrate and the polishing platen. The polishing platen is one of the most important factors that determine the material removal characteristics in DMP. Especially, it is known that the geometric characteristics of the polishing platen affects the material removal amount and its distribution. This paper investigated the material removal characteristics and the effects of the polishing platen groove in sapphire DMP. The experiments were preliminarily carried out to evaluate the sapphire material removal characteristics according to process parameters such as pressure, relative velocity and so on. In the experiment, the monitoring apparatus was applied to analyze process phenomena in accordance with the processing conditions. From the experimental results, the correlation was analyzed among process parameters, polishing phenomena and the material removal characteristics. The material removal equation based on phenomenological factors could be derived. And the experiment was followed to investigate the effects of platen groove on material removal characteristics.