Effect of Pressure on Edge Delamination in Chemical Mechanical Polishing of SU-8 Film on Silicon Wafer

Park, Sunjoon,Im, Seokyeon,Lee, Hyunseop Korean Tribology Society 2017 한국윤활학회지(윤활학회지) Vol.12 No.1

SU-8 is an epoxy-type photoresist widely used for the fabrication of high-aspect-ratio (HAR) micro-structures in micro-electro-mechanical systems (MEMS). To fabricate highly integrated structures, chemical mechanical polishing (CMP) has emerged as the preferred manufacturing process for planarizing the MEMS structure. In SU-8 CMP, an oxidizer decomposes organic impurities and particles in the CMP slurry remove the chemically reacted surface of SU-8. To fabricate HAR microstructures using the CMP process, the adhesion between SU-8 and substrate material is important to avoid the delamination of the SU-8 film caused by the mechanical-dominant material removal characteristic. In this study, the friction force during the CMP process is measured with a CMP monitoring system to detect the delamination phenomenon and investigate the delamination of the SU-8 film from the silicon substrate under various pressure conditions. The increase in applied pressure causes an increase in the frictional force and wafer-edge stress concentration. The frictional force measurement shows that the friction force changes according to the delamination phenomenon of the SU-8 film, and that it is possible to monitor the delamination phenomenon during the SU-8 CMP process. The delamination at a high applied pressure is explained by the effect of stress distribution and pad deformation. Consequently, it is necessary to control the pressure of polishing, which can avoid the delamination in SU-8 CMP.

Effect of Pressure on Edge Delamination in Chemical Mechanical Polishing of SU-8 Film on Silicon Wafer

Sunjoon Park,Seokyeon Im,Hyunseop Lee 한국트라이볼로지학회 2017 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.33 No.6

SU-8 is an epoxy-type photoresist widely used for the fabrication of high-aspect-ratio (HAR) microstructures in micro-electro-mechanical systems (MEMS). To fabricate highly integrated structures, chemical mechanical polishing (CMP) has emerged as the preferred manufacturing process for planarizing the MEMS structure. In SU-8 CMP, an oxidizer decomposes organic impurities and particles in the CMP slurry remove the chemically reacted surface of SU-8. To fabricate HAR microstructures using the CMP process, the adhesion between SU-8 and substrate material is important to avoid the delamination of the SU-8 film caused by the mechanical-dominant material removal characteristic. In this study, the friction force during the CMP process is measured with a CMP monitoring system to detect the delamination phenomenon and investigate the delamination of the SU-8 film from the silicon substrate under various pressure conditions. The increase in applied pressure causes an increase in the frictional force and wafer-edge stress concentration. The frictional force measurement shows that the friction force changes according to the delamination phenomenon of the SU-8 film, and that it is possible to monitor the delamination phenomenon during the SU-8 CMP process. The delamination at a high applied pressure is explained by the effect of stress distribution and pad deformation. Consequently, it is necessary to control the pressure of polishing, which can avoid the delamination in SU-8 CMP.

금형 소재용 다공질 재료의 개발과 특성 평가

박선준(Sunjoon Park),정성일(Sungil Chung),임용관(Yonggwan Im),정해도(Heado Jeong),이석우(Seckwoo Lee),최헌종(Honzong Choi) Korean Society for Precision Engineering 2004 한국정밀공학회지 Vol.21 No.6

At the large-sized mold for injection molding, the remaining gas in the mold causes some problems with final products. In order to solve these problems, air-bent was drilled on the surface of mold. However, this method leaves the scar on the surface of a product. Therefore, porous material was developed to the removal of remaining gas in this study. Porcerax II, which is a commercialized porous material, were developed in USA. It requires the electric discharge machining(EDM) process to make pores on the surface of the materials. The electric discharge machining (EDM) process, however, cause the increase of the time and cost for the fabrication of the mold. In this study, high speed machining(HSM) process was applied to the fabrication of porous mold without electric discharge machining(EDM) process. Some characteristics of the developed materials machined by high speed machining(HSM) and electric discharge machining(EDM) including air-permeability and porosity were compared with those of Porcerax II. Besides, in order to be applied to the molding process, hardness and tensile & yield strength were compared between Porcerax II and developed materials.

실리콘 웨이퍼 연삭 가공 공정 모니터링 시스템

박선준(Sunjoon Park),이상직(Sangjik Lee),정원덕(Wonduck Jung),정해도(Heado Jeong) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6

Recently, according to the development of semiconductor industry, needed to high-integration and highfunctionality. These changes are required for silicon wafer of large scale diameter and precision of TTV (Total Thickness variation). So, in this research, suggest that the method of monitoring system is using the motor current and AE sensor. This method is needed for observation of silicon wafer grinding process. This monitoring system is consisted of two parts. One is sensing part, the other is analysis part. Motor current sensor is used for detection of low frequency. AE sensor is used for detection of high frequency. Received original signal is converted to the digital, then, it is calculated RMS values, and then, it is analyzed in the computer. In this research, we tried to monitoring of motor current change and AE change. And then, it will be applied to analysis for silicon wafer grinding process.

Evaluation of environmental impacts during chemical mechanical polishing (CMP) for sustainable manufacturing

이현섭,Sunjoon Park,정해도 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.2

Reducing energy consumption has become a critical issue in manufacturing. The semiconductor industry in particular is confronted with environmental regulations on pollution associated with electric energy, chemical, and ultrapure water (UPW) consumptions. This paper presents the results of an evaluation of the environmental impacts during chemical mechanical polishing (CMP), a key process for planarization of dielectrics and metal films in ultra-large-scale integrated circuits. The steps in the CMP process are idling, conditioning, wetting, wafer loading/unloading, head dropping, polishing, and rinsing. The electric energy, CMP slurry, and UPW consumptions associated with the process and their impacts on global warming are evaluated from an environmental standpoint. The estimates of electric energy, slurry, and UPW consumptions as well as the associated greenhouse gas emissions presented in this paper will provide a technical aid for reducing the environmental burden associated with electricity consumption during the CMP process.

동분말이 함유된 에폭시 수지를 이용한 마이크로 기어의 제작에 관한 연구

정성일(Sungil Chung),박선준(Sunjoon Park),이인환(Inhwan Lee),정해도(Haedo Jeong),조동우(Dongwoo Cho) Korean Society for Precision Engineering 2004 한국정밀공학회지 Vol.21 No.12

In this paper, a new replication technique for a real 3D microstructure was introduced, in which a master pattern was made of photo-curable epoxy using a microstereolithography technology, and then it was transferred onto an epoxy-copper particle composite. A helical gear was selected as one of the real 3D microstructure for this study, and it was replicated from a pure epoxy to an epoxy composite. In addition, the transferability of the microreplication process was evaluated, and the properties of the epoxy composite were compared to that of the pure epoxy, including hardness, wear-resistance and thermal conductivity.

시뮬레이션 데이터를 이용한 정밀절대측위 정확도에 영향을 미치는 인자 분석

한중희(Joong-hee Han),노선준(Sunjoon No),권재현(Jay Hyoun Kwon),홍창기(Changki Hong),박지호(Chiho Park) 대한공간정보학회 2012 한국지형공간정보학회 학술대회 Vol.2012 No.5

국부가열에 따른 강재의 온도 및 강도 변화에 관한 실험적 연구

강성후,김민중,김성환,박선준,Kang. Sunghoo,Kim. Minjung,Kim. Sunghwan,Park. Sunjoon 한국방재학회 2013 한국방재학회논문집 Vol.13 No.6

본 연구에서는 전기적인 방법에 의해 강재가 국부 가열될 때 강재에 발생되는 열유지율을 정량적으로 평가하고, 국부적으로 가열된 강재의 강도특성 변화를 실험적 방법으로 규명하였다. 이를 위하여 두께 6 mm, 12 mm, 18 mm 강판 시험편을 사용하여 실험하였다. 제한적인 본 실험의 조건에서 강판의 온도는 최대 <TEX>$125.2^{\circ}C$</TEX>까지 상승하였으며 이곳으로부터 이격거리가 각각 200 mm, 400 mm인 위치에서 열유지율은 평균 22.9%와 18.4%로 각각 나타났다. 국부 가열된 강재의 인장강도 시험 결과, 강재 시험편의 두께에 상관없이 모두 SS400강재에 요구되는 인장강도 400 MPa과 항복강도 240 MPa을 모두 충족하였다. 연신율의 경우에는 모든 시험편에서 20~30%의 값을 보여 정상 범위에 있는 것으로 나타났다. 이러한 제한된 조건의 실내 실험 결과들로부터 강재가 <TEX>$20{\sim}120^{\circ}C$</TEX>의 온도 수준으로 국부 가열되는 경우 강재의 성능은 저하되지 않는 것으로 나타났다. In this study, the retention rate of heat that is generated when steel is locally heated by electrical means was quantitatively evaluated and changes in strength properties of the steel were investigated by experimentation. To do so, the experiment was conducted on specimens with thicknesses of 6 mm, 12 mm and 18 mm. With the limited conditions of this experiment, the steel plate was heated to at most <TEX>$125.2^{\circ}C$</TEX> and the average heat retention rates at 200 mm and 400 mm away from this measurement point were 22.9% and 18.4%, respectively. For the results of the tensile strength test of the locally heated steel, a tensile strength of 400 MPa and yielding strength of 240 MPa that are required from SS400 were all satisfied regardless of the thickness of the steel specimen. In the case of percent elongation, all specimens showed values of 20-30% being within the normal range. The results of the indoor experiment with such restricted conditions showed that the performance of steel is not diminished when locally heated to temperatures of <TEX>$20-120^{\circ}C$</TEX>.