Effect of Shear and Thermal Characteristics on Chemical Mechanical Polishing

Chemical mechanical polishing has been widely used to achieve global planarization of wafers. In this paper, an improved designed test rig is used to acquire the signals on chemical mechanical polishing. The shear force and temperature-rise are measured during chemical mechanical polishing process. The polishing temperature is measured by T-type thermocouples screwed behind the polishing interface of the carrier. The shear force is measured by a load transducer mounted on the lever and connected with the polishing head. The parameters including down force, rotation speed, particle size and volume flow rate of slurry are investigated. The experimental results provide a good index to end-point-detection. The theoretical simulation by the average lubrication equation coincides with the experimental results. This study contributes to the understanding of chemical mechanical polishing mechanism.

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Study on Nanoparticle Agglomeration During Chemical Mechanical Polishing (CMP) Performance

Journal of Nanofluids ◽

10.1166/jon.2021.1791 ◽

2021 ◽

Vol 10 (3) ◽

pp. 420-430

Author(s):

Mohammed A. Y. A. Bakier ◽

Keisuke Suzuki ◽

Panart Khajornrungruang

Keyword(s):

Chemical Mechanical Polishing ◽

Shear Force ◽

Removal Rate ◽

Thermal Characteristics ◽

Mechanical Polishing ◽

Reciprocal Relationship ◽

Surface Finishing ◽

Slurry Flow ◽

Nanoparticle Agglomeration ◽

Materials Used

The materials used in base fluids and nanoparticles are varied. One- and two-step manufacturing processes are used to create stable and highly conductive nanofluids. Both methods for making nanoparticle suspensions suffer from nanoparticle agglomeration, which is a major problem in any technique that uses nanopowders. As a result, the key to substantial surface finishing at planarization treatments and increase in the thermal characteristics of nanofluids is the production and suspension of almost non-agglomerated or monodispersed nanoparticles in liquids. This unfavorable aggregation is a major problem in nanopowder technology. Primary material constituents agglomerate rapidly overcoming the stable situation, and nanoparticle agglomerates set out in liquids, making it difficult to create nanofluids using two-step techniques. This research looks at the link between nanoparticle agglomeration during slurry flow and Material Removal Rate (MRR) during chemical mechanical polishing (CMP). The reciprocal relationship between MRR and the shear force exerted by the slurry flow was qualitatively elucidated by the researchers for the theoretical investigation. However, the present manipulation is focused on quantifying the shear stress exerted by nanoparticles floating in the slurry. As a result, the MRR-aggregation model is established based on the relationship between MRR and shear force. The experiment is being carried out to support this idea. The experimental results of aggregation and shear forces have been conducted by some recent studies. However, the extension to the real CMP is very promising for accomplishing a precise style of the removal mechanism and surface finishing criterion as well.

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Combined Diamond Disks in Chemical Mechanical Polishing

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.642.110 ◽

2015 ◽

Vol 642 ◽

pp. 110-114

Author(s):

Ming Yi Tsai ◽

J.K. Ho ◽

Jyu Lin Zeng

Keyword(s):

Chemical Mechanical Polishing ◽

Diamond Crystal ◽

Removal Rate ◽

Mechanical Polishing ◽

Experimental Results ◽

Polishing Process ◽

Diamond Grit ◽

Diamond Disk ◽

Crystal Shapes ◽

Chemical Mechanical Polishing Process

This paper presents a combined diamond disk that is designed and manufactured to markedly improve the leveling of diamond tips, thereby reducing the amount of diamond grit. First, a small brazed diamond disk was manufactured. Second, 12-or 24-disk brazed diamond disks were mounted onto a substrate with a diameter of 108 mm for completing the combined diamond disk. Four types of disks were fabricated, and their performances were compared with that of a conventional diamond disk. The experimental results showed that the combined diamond disk has more complete diamond crystal shapes and distribution with better leveling, which increases the effectiveness of the working diamond grits. Compared to a conventional diamond disk, the combined diamond disk achieved a higher wafer removal rate and better uniformity while consuming less pad material. The number of diamond grits required was significantly lower. Roughly, 7,600 and 12,000 diamond grits were used for the 24-and 12-disk brazed diamond disks, respectively, in the new disk, whereas 20,000 diamond grits were used in a conventional diamond disk. In the case of the conventional diamond disk, the diamond tips are leveled to more than 50 μm. However, in the case of the combined diamond disk, the diamond tips can be leveled to less than 30 μm because the diamond tips are already leveled. These results contribute to the understanding of conditioning techniques and further improvement of the chemical mechanical polishing process.

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Effect of Dressing Load and Speed on Removal Rate in the Chemical Mechanical Polishing Process

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.55-57.832 ◽

2011 ◽

Vol 55-57 ◽

pp. 832-837

Author(s):

Ming Yi Tsai ◽

W.K. Chen ◽

Hung Jung Tsai

Keyword(s):

Chemical Mechanical Polishing ◽

Removal Rate ◽

Polycrystalline Diamond ◽

Mechanical Polishing ◽

Experimental Results ◽

Polishing Process ◽

Random Orientation ◽

Diamond Disk ◽

Maximum Value ◽

Chemical Mechanical Polishing Process

A pad conditioner or diamond disk is needed to regenerate the asperity structure of the pad and recover its designated role in the chemical mechanical polishing process. In this paper, the effect of dressing load and speed on removal rate of oxidized wafers were investigated using a polycrystalline diamond disk and brazed diamond disk. It was found that polycrystalline diamond disk enable the manufacturer to tightly control diamond leveling and the cutter’s shape by comparison with a brazed diamond disk that contains discrete diamond grits of random orientation. Experimental results revealed that for polycrystalline diamond disk, the removal rate of oxidized wafer displayed an almost unchanged curve when the load was less than 4kg, but the removal rate of oxidized wafer for brazed diamond disk initially increased with the dressing load, reaching a maximum value at a dressing load of approximately 4 kg. Then, it decreased slowly with further increases of the dressing load. The removal rate of oxidized wafer remains unchanged with dressing speed.

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