• Tribology and Lubricants
• /
• 제34권6호
• /
• pp.226-234
• /
• 2018

Copper chemical mechanical planarization (CMP) has become a key process in integrated circuit (IC) technology. The results of copper CMP depend not only on the mechanical abrasion, but also on the slurry chemistry. The slurry used for Cu CMP is known to have greater chemical reactivity than mechanical material removal. The Cu CMP slurry is composed of abrasive particles, an oxidizing agent, a complexing agent, and a corrosion inhibitor. Citric acid can be used as the complexing agent in Cu CMP slurries, and is widely used for post-CMP cleaning. Although many studies have investigated the effect of citric acid on Cu CMP, no studies have yet been conducted on the interfacial friction characteristics and step height reduction in CMP patterns. In this study, the effect of citric acid on the friction characteristics and step height reduction in a copper wafer with varying pattern densities during CMP are investigated. The prepared slurry consists of citric acid ($C_6H_8O_7$), hydrogen peroxide ($H_2O_2$), and colloidal silica. The friction force is found to depend on the concentration of citric acid in the copper CMP slurry. The step heights of the patterns decrease rapidly with decreasing citric acid concentration in the copper CMP slurry. The step height of the copper pattern decreases more slowly in high-density regions than in low-density regions.

• 한국정밀공학회지
• /
• 제28권3호
• /
• pp.323-329
• /
• 2011

Certified reference materials (CRMs) have been used to calibrate surface profilers for reliable measurements. In this paper, we present a newly designed step height CRM which has a step height pattern with two different widths and various special patterns for checking radial magnification, distortion of optical viewing systems, etc. Especially, it could be useful for multi-probe inspection instruments in the manufacturing lines. The fabrication was done by conventional optical lithography and dry etching process with optimized conditions. To verify the step height values, a white-light scanning interferometer was used with objective lenses having magnification of $10{\times}$ and $100{\times}$. CRMs with nominal step heights of $0.5\;{\mu}m$, $1\;{\mu}m$, $3\;{\mu}m$, $5\;{\mu}m$, $7\;{\mu}m$, and $10\;{\mu}m$ were fabricated and the uniformity of these CRMs was evaluated to be less than 3 nm ($1{\sigma}$).

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1997년도 추계학술대회 논문집
• /
• pp.935-938
• /
• 1997

Recently, the minimum line width shows a tendency to decrease and the multi-level increase in semiconductor. Therefore, a planarization technique is needed and chemical mechanical polishing(CMP) is considered as one of the most suitable process. CMP accomplishes a high polishing performance and a global planarization of high quality. But there are several defects in CMP such as micro-scratches, abrasive contaminations, and non-uniformity of polished wafer edges. Wet etching include of Spin-etching can improve he defects of CMP. It uses abrasive-free chemical solution instead of slurry. On this study, ILD(INterlayer-Dielectric) was removed by CMP and wet-etching methods in order to investigate the superiority of wet etching mechanism. In the thin film wafer, the results were evaluated at a viewpoint of material removal rate(MRR) and within wafer non-uniformity(WIWNU). And pattern step height was also compared for planarization characteristics of the patterned wafer.

• 한국정밀공학회지
• /
• 제13권11호
• /
• pp.46-56
• /
• 1996

Planarization technique is rapidly recognized as a critical step in chip fabrication due to the increase in wiring density and the trend towards a three dimensional structure. Global planarity requires the preferential removal of the projecting features. Also, the several materials i.e. Si semiconductor, oxide dielectric and sluminum interconnect on the chip, should be removed simultaneously in order to produce a planar surface. This research has investihgated the development of the chemical mechanical polishing(CMP) machine with uniform pressure and velocity mechanism, and the pad insensitive to pattern topography named hard grooved(HG) pad for global planarization. Finally, a successful result of uniformity less than 5% standard deviation in residual oxide film and planarity less than 15nm in residual step height of 4 inch device wafer, is achieved.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
• /
• pp.585-590
• /
• 2000

Recently, It is gradually raised necessity that thickness of thin film is measured accuracy and managed in industrial circles and medical world. Ultrasonic Signal processing method is likely to become a very powerful method for NDE method of detection of microdefects and thickness measurement of thin film below the limit of Ultrasonic distance resolution in the opaque materials, provides useful information that cannot be obtained by a conventional measuring system. In the present research, considering a thin film below the limit of ultrasonic distance resolution sandwiched between three substances as acoustical analysis model, demonstrated the usefulness of ultrasonic Signal processing technique using information of ultrasonic frequency for NDE of measurements of thin film thickness, sound velocity, and step height, regardless of interference phenomenon. Numeral information was deduced and quantified effective information from the image. Also, pattern recognition of a defected input image was performed by neural network algorithm. Input pattern of various numeral was composed combinationally, and then, it was studied by neural network. Furthermore, possibility of pattern recognition was confirmed on artifical defected input data formed by simulation. Finally, application on unknown input pattern was also examined.

• 한국항행학회논문지
• /
• 제21권1호
• /
• pp.132-137
• /
• 2017

본 논문에서는 로봇의 구조나 보행 상황을 반영해 하나의 보행 패턴을 다른 보행 패턴으로 변환하게 해주는 영모멘트 점 (ZMP; zero moment point)와 질량 중심 (CoM; center of mass)의 실시간 변환 방법을 제안한다. 일반적으로 휴머노이드 로봇은 높이와 질량과 같은 자체적인 구조 특성을 가지고 있다. 이러한 구조적 특성으로 인해 인간 또는 휴머노이드 로봇으로부터 측정되거나 생성되어진 CoM / ZMP 보행 패턴을 다른 로봇에 직접 적용하는 것은 어렵다. 이를 위하여 간단한 휴머노이드 로봇 모델인 cart-table model을 사용해 보폭의 길이, 보행 시간, CoM 높이 변화에 따라 보행 패턴의 특성을 분석한다. 그러한 분석으로부터 변환 방정식을 유도하고 시뮬레이션을 통해 제안된 방법을 검증한다.

• 복식
• /
• 제42권
• /
• pp.127-136
• /
• 1999

This study purport to establish the size was flexibly receptive to consumers. Sample size was 6555 women in their 20's and 29 variables from the diret anthropometric data were applied to analyze. The preliminary survey was taken from Febraury 10. 1997 to May 23 1997 and the measurement was done from April 14, 1997 to June 10. 1997. Follwing the KS regulations Hanbok were given 3cm intervals each for the bust and hip girth and cm for th height. Size system was presented for the usage of developing the pattern of hanbok by analyzing the result of the regression coefficient and referring to the distribution chart of the back length and the neck to ulnar styloid length. When establishing the standard size for the ready-made Hanbok like Western style clothes it's convenient for both consumer and producer to present both bust girth and height. To enhance the fitting of Chogori we used the flatness ratio of bust as the reference for grouping styles of body. in the case of Chima-\ulcorner해갸 4 brackets are developed. First step was bust girth 78cm height 15cm second was bust girth 5852cm5 height 160cm third was bust girth 82cm height 165cm fourth was bust girth 88cm height 16cm.

• The Journal of Korean Physical Therapy
• /
• 제23권5호
• /
• pp.15-21
• /
• 2011

Purpose: The purpose of this study was to describe the influence of respiration on the segmental motion of the lumbar spine in the lying position. Methods: Twelve healthy females without a history of low back pain participated. Lumbosacral lordosis, intervertebral body angles, intervertebral body displacements, and anterior heights of the intervertebral disc of the lumbar spine were measured at inspiration, expiration and forced expiration in the supine and prone positions via fluoroscopy. Results: The results of lumbar kinematic analysis in the supine position according to respiration pattern were as follows. The L4/5 intervertebral body angle was significantly higher at forced expiration than at expiration (p<0.05). The L3/4 anterior height of the intervertebral disc was significantly higher at expiration than at forced inspiration and the L5/S1 anterior height of the intervertebral disc was significantly higher at inspiration than at forced expiration (p<0.05). There were no significant differences in the intervertebral body displacements and lumbosacral lordosis in the supine position (p>0.05). The results of lumbar kinematic analysis in the prone position according to respiration pattern were as follows. The L5/S1 anterior height of the intervertebral disc was significantly higher at inspiration than at forced expiration (p<0.05). However, there was no significant difference in the intervertebral body angle, the intervertebral body displacements, and the lumbosacral lordosis (p>0.05). Conclusion: These findings suggested that respiration can affect the intervertebral body angle and anterior height of the intervertebral disc in some segments. The results from this study serve as a step in the development of guidelines for lumbar kinematic analysis for lumbar breathing training.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
• /
• pp.93-94
• /
• 2005

Cu metallization using electrochemical plating(ECP) has played an important role in back end of line(BEOL) interconnect formation. In this work, we studied the optimized copper thickness using Bottom-up Gap-fill in Cu ECP, which is closely related with the pattern dependencies in Cu ECP and Cu dual damascene process at 0.13 ${\mu}m$ technology node. In order to select an optimized Cu ECP thickness, we examined Cu ECP bulge, Cu CMP dishing and electrical properties of via hole and line trench over dual damascene patterned wafers split into different ECP Cu thickness.

• 대한기계학회논문집B
• /
• 제25권9호
• /
• pp.1253-1262
• /
• 2001

Experimental study is conducted to investigate the heat/mass transfer and flow characteristics for the flow over backward-facing step and cavities. A naphthalene sublimation method has been employed to measure the mass transfer coefficients on the duct wall and LDV system has been used to obtain mean velocity profiles and turbulence intensities. Reynolds number based on the step height and free stream velocity is 20,000 and St numbers of acoustic excitations given to separated flow are 0.2 to 0.4. The spectra of streamwise velocity fluctuation show a sharp peak forcing frequency for an acoustically excited flow. The results reveal that the vortex pairing and overall turbulence level are enhanced by the acoustic excitation and a significant decrease in the reattachment length and the increased turbulence intensity are observed with the excitation. A certain acoustic excitation increases considerably the heat/mass transfer coefficient at the reattachment point and in the recirculation region. For the cavities, heat/mass transfer is enhanced by the acoustic excitation due to the elevated turbulence intensity. For the 10H cavity, the flow pattern is significantly changed with the acoustic excitation. However, for the 5H cavity, the acoustic excitation has little effect on the flow pattern in the cavity.