Novel SiC wafer manufacturing process employing three-step slurryless electrochemical mechanical polishing

Abstract Slurryless electrochemical mechanical polishing (ECMP) is very effective in the polishing of silicon carbide (SiC) wafers. To achieve a high material removal rate (MRR) of SiC wafer using ECMP with low electrical energy loss, charge utilization efficiency in the anodic oxidation of the SiC surface was investigated and the underlying mechanism was clarified by modeling the anodic oxidation system of SiC in 1 wt% NaCl aqueous solution. The charge utilization efficiency in the anodic oxidation of SiC was found to be constant when the current density was less than 20 mA/cm2 and significantly decreased when the current density was greater than 30 mA/cm2, resulting in a significant reduction in the MRR. Modeling of the anodic oxidation system indicates that the charge utilization efficiency depended on the potential applied on the SiC surface: the oxidation of SiC occupied the dominant position in the anodizing system when the potential is lower than 25 V vs Ag|AgCl, charge utilization efficiency greatly decreased when the applied potential was greater than 25 V owing to the occurrence of oxidations of the H2O and Cl-. This research provides both a theoretical and practical foundation for using ECMP to polish SiC wafers.

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Mechanism Analysis of Chemical Mechanical Polishing of 4H-SiC Wafer

2020 China Semiconductor Technology International Conference (CSTIC) ◽

10.1109/cstic49141.2020.9282432 ◽

2020 ◽

Author(s):

Gaoyang Zhao ◽

Aoxue Xu ◽

Fan Xu ◽

Daohuan Feng ◽

WeiliLiu ◽

...

Keyword(s):

Chemical Mechanical Polishing ◽

Mechanical Polishing ◽

Mechanism Analysis ◽

Sic Wafer

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Basic experimental investigation of pulsed electrochemical mechanical polishing process

Surface Engineering ◽

10.1179/174329409x397796 ◽

2009 ◽

Vol 25 (7) ◽

pp. 535-540 ◽

Cited By ~ 3

Author(s):

J. J. Yi ◽

C. M. Chen ◽

X. Q. Tian ◽

B. Y. Ji

Keyword(s):

Experimental Investigation ◽

Mechanical Polishing ◽

Polishing Process ◽

Electrochemical Mechanical Polishing

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Effect of Process Parameters on Material Removal Rate in Chemical Mechanical Polishing of 6H-SiC(0001)

Materials Science Forum ◽

10.4028/www.scientific.net/msf.600-603.831 ◽

2008 ◽

Vol 600-603 ◽

pp. 831-834 ◽

Cited By ~ 9

Author(s):

Joon Ho An ◽

Gi Sub Lee ◽

Won Jae Lee ◽

Byoung Chul Shin ◽

Jung Doo Seo ◽

...

Keyword(s):

Material Removal Rate ◽

Chemical Mechanical Polishing ◽

Material Removal ◽

Colloidal Silica ◽

Removal Rate ◽

Mechanical Polishing ◽

Diamond Particles ◽

Average Grain Size ◽

Silica Slurry ◽

Sic Wafer

2inch 6H-SiC (0001) wafers were sliced from the ingot grown by a conventional physical vapor transport (PVT) method using an abrasive multi-wire saw. While sliced SiC wafers lapped by a slurry with 1~9㎛ diamond particles had a mean height (Ra) value of 40nm, wafers after the final mechanical polishing using the slurry of 0.1㎛ diamond particles exhibited Ra of 4Å. In this study, we focused on investigation into the effect of the slurry type of chemical mechanical polishing (CMP) on the material removal rate of SiC materials and the change in surface roughness by adding abrasives and oxidizer to conventional KOH-based colloidal silica slurry. The nano-sized diamond slurry (average grain size of 25nm) added in KOH-based colloidal silica slurry resulted in a material removal rate (MRR) of 0.07mg/hr and the Ra of 1.811Å. The addition of oxidizer (NaOCl) in the nano-size diamond and KOH based colloidal silica slurry was proven to improve the CMP characteristics for SiC wafer, having a MRR of 0.3mg/hr and Ra of 1.087Å.

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Experimental Research of Electrochemical Mechanical Polishing (ECMP) for Micro Tool Electrode

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.314-316.1846 ◽

2011 ◽

Vol 314-316 ◽

pp. 1846-1850 ◽

Cited By ~ 1

Author(s):

Shuai Guo ◽

Z.N Guo ◽

Hong Ping Luo ◽

Wen Cai Gu

Keyword(s):

Experimental Research ◽

Process Parameters ◽

Mechanical Polishing ◽

Working Fluid ◽

Tool Electrode ◽

Electrical Parameters ◽

Electrochemical Mechanical Polishing ◽

Major Process ◽

Micro Tool ◽

Quantitative Analyses

The mechanism of the elctrochemical mechanical polishing (ECMP) technology for micro tool electrode was investigated. In this paper, suitable major process parameters on the surface quality were evaluated, the major parameters contains electrical parameters, machining gap, the working fluid and other factors. In quantitative analyses, the process of the ECMP technology were conducted. The roughness of the workpiece was reduced from a relatively high value to a mirror effect.

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