scholarly journals Contrast Experiments in Dielectrophoresis Polishing (DEPP)/Chemical Mechanical Polishing (CMP) of Sapphire Substrate

2019 ◽  
Vol 9 (18) ◽  
pp. 3704 ◽  
Author(s):  
Tianchen Zhao ◽  
Julong Yuan ◽  
Qianfa Deng ◽  
Kaiping Feng ◽  
Zhaozhong Zhou ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Sapphire Substrate ◽  
Chemical Mechanical Polishing ◽  
Mechanical Polishing ◽  
Uniform Electric Field ◽  
Maximum Increase ◽  
Sapphire Surface ◽  
Sapphire Substrates ◽  
Better Than ◽  
Surface Changes

The broad applications of sapphire substrates in many fields warrants an urgent demand for a highly efficient and high precision polishing method for the sapphire substrates. The authors proposed a novel sapphire substrate polishing method that is based on the dielectrophoresis (DEP) effect. The principle of dielectrophoresis polishing (DEPP) is described. A non-uniform electric field was added in the polishing area to drive abrasives moving in the direction towards the plate by the DEP force. The amount of abrasives that participates in the polishing action increases as the distribution of polishing slurry on sapphire surface changes, leading towards the improvement of sapphire polishing both in quality and efficiency. Comparative experiments between DEPP and traditional chemical mechanical polishing (CMP) were carried out. It was found that the maximum increase of sapphire MRR for DEPP is 71%, reaching 13 mg/h, and the minimum increase was 9.5%, reaching 4.6 mg/h. The surface roughness of the sapphire substrate decreases faster and more uniform with DEPP. The final surface roughness of the sapphire substrate after DEPP was Ra 0.87 nm and the flatness was 0.3078 waves (RMS value), which is better than 0.6863 waves (RMS value) of sapphire substrate with traditional CMP polishing.

Development of TSV Reveal Process Using Very Fine Si/Cu Grinding and Metal Contamination Removal

2015 ◽  
Vol 2015 (DPC) ◽  
pp. 001928-001955
Author(s):  
Naoya Watanabe ◽  
Masahiro Aoyagi ◽  
Daisuke Katagawa ◽  
Tsubasa Bandoh ◽  
Takahiko Mitsui ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Chemical Mechanical Polishing ◽  
Metal Contamination ◽  
Mechanical Polishing ◽  
Grinding Wheel ◽  
Average Surface Roughness ◽  
Average Surface ◽  
3D Ics ◽  
Cu Contamination ◽  
Contamination Removal

Three-dimensional integrated circuits (3D-ICs) using through silicon via (TSV) have been developed as an emerging technology that can lead to significant progress (1–4). Among various TSV processes, the via-middle process has potential for wide spread use because formation of small-sized TSVs is relatively easy in the via-middle process. However, TSV reveal process must be performed for electrical contact in the via-middle process. This TSV reveal process is important because it can influence the metal contamination and stacking yield of 3D-ICs. Conventionally, TSV reveal is performed by Si grinding and Si dry etching (5). A disadvantage of that method is the resultant TSV depth deviation, which can cause bonding failure during wafer/chip stacking. In (6), TSV leveling was performed by introducing a chemical mechanical polishing (CMP) step after deposition of the backside insulator. However, the revealed TSVs break during CMP step if they exceed a certain height. To overcome these problems, we developed a novel TSV reveal process comprising direct Si/Cu grinding and metal contamination removal (7,8). First, simultaneous grinding of Cu and Si was performed using a novel vitrified grinding wheel. In situ cleaning with a high-pressure micro jet and the inelastic porous structure of the grinding wheel suppressed the adhesion of Cu contaminants to the Si, and TSVs were leveled and exposed. Next, an electroless Ni-B film was deposited on the Cu surface of the TSVs. The Si was etched with an alkaline solution, whereas the Cu was protected by the Ni-B film. An insulator was deposited, and then the insulator on the top surface of the TSV was removed. We achieved the backside reveal of TSVs without TSV depth deviation and suppressed Cu contamination to less than 1e11 atoms/cm2. However, after direct Si/Cu grinding with an 8000 grit grinding wheel, the average surface roughness of Si was 5–10 nm, which is larger than that after chemical mechanical polishing (CMP). In this paper, we developed vitrified grinding wheels with very high grit numbers (#30,000 and #45,000) and present an improved version of our TSV reveal process. The average surface roughness of Si after Si/Cu grinding was approximately 3 nm for the 30,000 grit grinding wheel and 1 nm for the 45,000 grit grinding wheel. This value is equivalent to that after CMP. The improved process produced a uniform reveal of 4-um-diameter TSVs without TSV depth deviation and Cu contamination. The Cu contaminant concentration on Si region between TSVs was small (<3e10 atoms/cm2). This process will reduce the cost of the TSV reveal process and considerably improve the TSV yield.

Blade Diamond Disk for Conditioning CMP Polishing Pad

2010 ◽  
Vol 97-101 ◽  
pp. 3-6 ◽  
Author(s):  
Ming Yi Tsai
Keyword(s):  
Surface Roughness ◽  
Epoxy Resin ◽  
Chemical Mechanical Polishing ◽  
Polycrystalline Diamond ◽  
Mechanical Polishing ◽  
Height Variation ◽  
Surface Textures ◽  
Diamond Disk ◽  
Diamond Conditioner ◽  
The Cost

A diamond conditioner or dresser is needed to regenerate the asperity structure of the pad and recover its designed ability in chemical mechanical polishing (CMP) process. In this paper a new design of diamond conditioner is made by shaping a sintered matrix of polycrystalline diamond (PCD) to form teethed blades. These blades are arranged and embedded in epoxy resin to make a designed penetration angle, called the blade diamond disk. The dressing characteristics of pad surface textures are studied by comparison with conventional diamond conditioner. It is found that the height variation of the diamond tip of blade diamond disk is significantly smaller than the conventional diamond disk. The dressing rate of blade diamond disk is lower than that of the conventional diamond disk, and hence the pad life is prolonged. As a result, reduction of the cost CMP is expected. In addition the pad surface roughness Ra of about 3.79μm is less than Ra of about 4.15μm obtained after dressing using a conventional diamond disk.

Chemical Mechanical Polishing of Cu Pattern Wafer Based Alkaline Slurry in GLSI with R(NH2)n as Complexing Agent

2011 ◽  
Vol 236-238 ◽  
pp. 3020-3023 ◽  
Author(s):  
Yan Gang He ◽  
Xiao Wei Gan ◽  
Wei Hong ◽  
Yi Hu ◽  
Yu Ling Liu
Keyword(s):  
Reaction Mechanism ◽  
Chemical Mechanical Polishing ◽  
Mechanical Polishing ◽  
Complexing Agents ◽  
Complexing Agent ◽  
Mechanism Analysis ◽  
Slurry Stability ◽  
Cu Cmp ◽  
Better Than

Chemical mechanical polishing (CMP) of Cu pattern wafer based alkaline slurry in GLSI with R(NH2)n as complexing agent was investigated. In Cu CMP procedure, it is necessary to minimize the surface dishing and erosion while maintaining good planarity. This requirements are met through the complexing agents. Based on the reaction mechanism analysis of Cu in alkaline slurry with R(NH2)n as complexing agent in CMP, the performance of Cu dishing and erosion were discussed. The results showed that the slurry stability can be improved obviously by the addition of R(NH2)n as complexing agent, both Cu1 and Cu2 have good dishing and erosion performance. Furthermore, the dishing condition of Cu2 (180-230nm) is better than that of Cu1 (280-370nm), and the erosion condition of Cu2 (230-260nm) is also better than that of Cu1 (450-500nm).

Effect of Sr(OH)2 as a pH Regulator on Different Plane Sapphire Substrate Chemical Mechanical Polishing

2019 ◽  
Vol 8 (2) ◽  
pp. P63-P69 ◽  
Author(s):  
Da Yin ◽  
Xinhuan Niu ◽  
Liu Yang ◽  
Kai Zhang ◽  
Jianchao Wang ◽  
...  
Keyword(s):  
Sapphire Substrate ◽  
Chemical Mechanical Polishing ◽  
Mechanical Polishing

Two-Step Chemical Mechanical Polishing of Sapphire Substrate

2010 ◽  
Vol 157 (6) ◽  
pp. H688 ◽  
Author(s):  
Zefang Zhang ◽  
Weili Liu ◽  
Zhitang Song ◽  
Xiaokai Hu
Keyword(s):  
Sapphire Substrate ◽  
Chemical Mechanical Polishing ◽  
Mechanical Polishing
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