• 한국전기전자재료학회논문지
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• 제20권1호
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• pp.74-79
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• 2007

Most studies on copper Chemical Mechanical Planarization (CMP) have focused on material removal and its mechanisms. Although many studies have been conducted on the mechanism of Cu CMP, a study on uniformity in Cu CMP is still unknown. Since the aim of CMP is global and local planarization, the approach to various factors related to uniformity in Cu CMP is essential to elucidate the Cu CMP mechanism as well. The main purpose of the experiment reported here was to investigate and mechanically analyze the roles of slurry components in the formation of the uniformity in Cu CMP. In this paper, Cu CMP was performed using citric acid($C_{6}H_{8}O_{7}$), hydrogen peroxide($H_{2}O_{2}$), colloidal silica, and benzotriazole($BTA,\;C_{6}H_{4}N_{3}H$) as a complexing agent, an oxidizer, an abrasive, and a corrosion inhibitor, respectively. All the results of this study showed that within-wafer non-uniformity(WIWNU) of Cu CMP could be controlled by the contents of slurry components.

• KSTLE International Journal
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• 제5권1호
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• pp.32-35
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• 2004

The purpose of this study is to investigate the effects of the structure and mechanical properties of laser-processed pads on their polishing behavior such as their removal rate and WIWNU (within wafer non-uniformity) during the chemical mechanical planarization (CMP) process. The holes on the pad acted as the reservoir of slurry particles and enhanced the removal rate. Without grooves, no effective removal of wafers was possible. When the length of the circular-type grooves was increased, higher removal rates and lower wafer non-uniformity were measured. The removal rate and non-uniformity linearly increased as the elastic modulus of the top pad increased. Higher removal rates and lower non-uniformity were measured as the hardness of the pad increased.

• Tribology and Lubricants
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• 제37권6호
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• pp.213-223
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• 2021

Electrochemical mechanical planarization (ECMP) was developed to overcome the shortcomings of conventional chemical mechanical planarization (CMP). Because ECMP technology utilizes electrochemical reactions, it can have a higher efficiency than CMP even under low pressure conditions. Therefore, there is an advantage in that it is possible to reduce dicing and erosions, which are physical defects in semiconductor CMP. This paper summarizes the papers on ECMP published from 2003 to 2021 and analyzes research trends in ECMP technology. First, the material removal mechanisms and the configuration of the ECMP machine are dealt with, and then ECMP research trends are reviewed. For ECMP research trends, electrolyte, processing variables and pads, tribology, modeling, and application studies are investigated. In the past, research on ECMP was focused on basic research for the development of electrolytes, but it has recently developed into research on tribology and process variables and on new processing systems and applications. However, there is still a need to increase the processing efficiency, and to this end, the development of a hybrid ECMP processing method using another energy source is required. In addition, ECMP systems that can respond to the developing metal 3D printing technology must be researched, and ECMP equipment technology using CNC and robot technology must be developed.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권7호
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• pp.311-315
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• 2002

Chemical mechanical polishing (CMP) process was required for the global planarization of inter-metal dielectric(IMD), inter-level dielectric (ILD) layers of multi-layer interconnections. In this paper, we studied the characteristics of polishing pad, which can apply shallow trench isolation (STI)-CMP process for global planarization of multi-level interconnection structure. Also, we investigated the effects of different sets of polishing pad, such as soft and hard pad. As an experimental result, hard pad showed center-fast type, and soft pad showed edge-fast type. Totally, the defect level has shown little difference, however, the counts of scratch was detected less than 2 on JR111 pad. Through the above results, we can select optimum polishing pad, so we can expect the improvements of throughput and device yield.

• 한국입자에어로졸학회지
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• 제12권4호
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• pp.145-150
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• 2016

During the chemical mechanical planarization (CMP) process, slurry that comprises abrasive particles can directly affect the CMP performance and quality. Mainly, the large particles in the slurry can generate the defects on the wafer. Thus, many kinds of filters have been used in the CMP process to remove unwanted over-sized particles. Among these filters, the point-of-use (POU) filter is used just before the slurry is supplied onto the CMP pad. In the CMP research field, analysis of the POU filter has been relatively exceptional, and previous studies have not focused on the standardized filtration efficiency (FE) or filter performance. Furthermore, conventional evaluation methods of filter performance are not appropriate for POU filters, as the POU filter is not a membrane type, but is instead a depth type roll filter. In order to accurately evaluate the POU filter, slurry FE according to particle size was measured in this study. Additionally, a CMP experiment was conducted with filtered slurry to demonstrate the effects of filtered slurry on CMP performance. Depending on the flow rate and the filter retention size, the FE according to particle size was different. When the small and large particles have different FEs, the total filtration efficiency (TFE) can still have a similar value. For this reason, there is a need to measure the FE with respect to the particle size to verify the effects of the POU filter on the CMP process.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.33-36
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• 2001

Chemical mechanical polishing(CMP) process has been widely used to planarize dielectric layers, which can be applied to the integrated circuits for deep sub-micron technology. The rise throughput and the stability in the device fabrication can be obtained by applying of CMP process to STI structure in 0.18$\mu\textrm{m}$ m semiconductor device. The reverse moat process has been added to employ in of each thin films in STI-CMP was not equal, hence the devices must to be effected, that is, the damage was occurred in the device area for the case of excessive CMP process and the nitride film was remained on the device area for the case of insufficient CMP process, and than, these defects affect the device characteristics. Also, we studied the High Selectivity Slurry(HSS) to perform global planarization without reverse moat step.

• 한국정밀공학회지
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• 제13권11호
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• pp.46-56
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• 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.

• 한국재료학회지
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• 제16권12호
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• pp.731-738
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• 2006

It is seriously considered using Al CMP (chemical mechanical planarization) process for the next generation 45 nm Al wiring process. Al CMP is known that it has a possibility of reducing process time and steps comparing with conventional RIE (reactive ion etching) method. Also, it is more cost effective than Cu CMP and better electrical conductivity than W via process. In this study, we investigated 4 different kinds of slurries based on abrasives for reducing scratches which contributed to make defects in Al CMP. The abrasives used in this experiment were alumina, fumed silica, alkaline colloidal silica, and acidic colloidal silica. Al CMP process was conducted as functions of abrasive contents, $H_3PO_4$ contents and pressures to find out the optimized parameters and conditions. Al removal rates were slowed over 2 wt% of slurry contents in all types of slurries. The removal rates of alumina and fumed silica slurries were increased by phosphoric acid but acidic colloidal slurry was slightly increased at 2 vol% and soon decreased. The excessive addition of phosphoric acid affected the particle size distributions and increased scratches. Polishing pressure increased not only the removal rate but also the surface scratches. Acidic colloidal silica slurry showed the highest removal rate and the lowest roughness values among the 4 different slurry types.

• 한국진공학회지
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• 제10권3호
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• pp.361-367
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• 2001

CMP(Chemical Mechanical Polishing)는 반도체 소자 제조공정 중 다층 배선구조의 평탄 경면화에 널리 이용되고 있다. 차세대 웨이퍼로 각광받는 SOI(Silicon On Insulator) 웨이퍼 제조공정 중 웨이퍼 표면 미소 거칠기를 개선하기 위해서 본 논문에서는 여러 가지 가공변수(슬러리와 연마패드)에 따른 CMP 연마능률과 표면 미소 거칠기 변화에 대해 연구하였다. 결과적으로 연마능률은 슬러리의 입자 크기가 증가할수록 이에 따라 증가하였으며, 미소 거칠기는 슬러리의 연마입자보다는 연마패드에 영향이 더욱 지배적이다. AFM(Atomic Force Microscope)에 의한 평가에서 표면 미소 거칠기가 27 $\AA$ Rms에서 0.64 $\AA$ Rms로 개선됨을 확인할 수 있었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.49-50
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• 2006

The studies on Cu CMP have focused on material removal and its mechanisms. Although many studies have been conducted on the mechanism of Cu CMP, a study on uniformity in Cu CMP is still unknown. Since the aim of CMP is global and local planarization, the approach to uniformity in Cu CMP is essential to elucidate the Cu CMP mechanism as well. The main purpose of the experiment reported here was to investigate the roles of slurry components in the formation of the uniformity in Cu CMP. All the results of in this study showed that the uniformity in Cu CMP could be controlled by the contents of slurry components.