Development of Highly Efficient Combined Polishing Method for Single-Crystal Silicon Carbide

2017 ◽  
Vol 5 (3) ◽  
Author(s):  
Tsuneo Kurita ◽  
Koji Miyake ◽  
Kenji Kawata ◽  
Kiwamu Ashida ◽  
Tomohisa Kato
Keyword(s):  
Silicon Carbide ◽  
Single Crystal ◽  
Electrochemical Machining ◽  
Single Crystal Silicon ◽  
High Hardness ◽  
Sio2 Layer ◽  
Electrochemical Technique ◽  
Crystal Silicon ◽  
Abrasive Particles ◽  
The Relationship

The aim of this research is to develop a combined polishing technology for single-crystal silicon carbide (SiC) wafers, which is known to be difficult to process due to its high hardness. This paper proposes a combined polishing method based on converting SiC into a material with a relatively low hardness and then polishing this material using abrasive particles with a higher hardness. An electrochemical technique was tried to reduce the hardness of SiC. The effectiveness of the combined technique is experimentally demonstrated. In addition, the temporal changes of the thickness of SiO2 layer and the relationship between the electrochemical machining current and the thickness of SiO2 layer are shown.

Development of New Complex Machining Technology for Single Crystal Silicon Carbide Polishing

2016 ◽  
Vol 10 (5) ◽  
pp. 786-793
Author(s):  
Tsuneo Kurita ◽  
◽  
Koji Miyake ◽  
Kenji Kawata ◽  
Kiwamu Ashida ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Single Crystal ◽  
Semiconductor Device ◽  
Single Crystal Silicon ◽  
High Hardness ◽  
Electrochemical Technique ◽  
Crystal Silicon ◽  
Abrasive Particles ◽  
Power Semiconductor ◽  
Device Applications

Single-crystal, silicon carbide (SiC) wafers surpass silicon in terms of voltage resistance and heat resistance, and show promise for use in power semiconductor device applications. The aim of this research is to develop a complex machining technology for SiC, which is known to be difficult to process owing to its high hardness. This paper proposes a complex machining method based on converting SiC into a material with a relatively low hardness, and then polishing it using abrasive particles with a higher hardness. The proposed polishing method uses either a photodissociation or an electrochemical technique to reduce the hardness of SiC. The effectiveness of the combined technique is experimentally demonstrated. In addition, a method is proposed for monitoring the processing state by measuring the electric current.

scholarly journals Novel Abrasive-Impregnated Pads and Diamond Plates for the Grinding and Lapping of Single-Crystal Silicon Carbide Wafers

2021 ◽  
Vol 11 (4) ◽  
pp. 1783
Author(s):  
Ming-Yi Tsai ◽  
Kun-Ying Li ◽  
Sun-Yu Ji
Keyword(s):  
Silicon Carbide ◽  
Wear Rate ◽  
Single Crystal ◽  
Traditional Method ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Single Crystal Silicon ◽  
Crystal Silicon ◽  
Diamond Grit ◽  
Ceramic Binder

In this study, special ceramic grinding plates impregnated with diamond grit and other abrasives, as well as self-made lapping plates, were used to prepare the surface of single-crystal silicon carbide (SiC) wafers. This novel approach enhanced the process and reduced the final chemical mechanical planarization (CMP) polishing time. Two different grinding plates with pads impregnated with mixed abrasives were prepared: one with self-modified diamond + SiC and a ceramic binder and one with self-modified diamond + SiO2 + Al2O3 + SiC and a ceramic binder. The surface properties and removal rate of the SiC substrate were investigated and a comparison with the traditional method was conducted. The experimental results showed that the material removal rate (MRR) was higher for the SiC substrate with the mixed abrasive lapping plate than for the traditional method. The grinding wear rate could be reduced by 31.6%. The surface roughness of the samples polished using the diamond-impregnated lapping plate was markedly better than that of the samples polished using the copper plate. However, while the surface finish was better and the grinding efficiency was high, the wear rate of the mixed abrasive-impregnated polishing plates was high. This was a clear indication that this novel method was effective and could be used for SiC grinding and lapping.

scholarly journals Experimental Research on Discharge Forming Cutting-Electrochemical Machining of Single-Crystal Silicon

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Bin Xin ◽  
Wei Liu
Keyword(s):  
Surface Roughness ◽  
Single Crystal ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Electrochemical Machining ◽  
Single Crystal Silicon ◽  
Recast Layer ◽  
Movement Speed ◽  
Crystal Silicon ◽  
Wedm Process

During the wire electrical discharge machining (WEDM) process, a large number of discharge pits and a recast layer are easily generated on the workpiece surface, resulting in high surface roughness. A discharge forming cutting-electrochemical machining method for fabricating single-crystal silicon is proposed in this study to solve this problem. On the same processing equipment, single-crystal silicon is first cut using the discharge forming cutting method. Second, electrochemical anodic reaction technology is used to dissolve the discharge pits and recast layer on the single-crystal silicon surface. The machining mechanism of this process, the surface elements of the processed single-crystal silicon and a comparison of the kerf width are analyzed through experiments. On this basis, the influence of the movement speed of the copper foil electrode during electrochemical anodic dissolution on the final surface roughness is qualitatively analyzed. The experimental results show that discharge forming cutting-electrochemical machining can effectively eliminate the electrical discharge pits and recast layer, which are caused by electric discharge cutting, on the surface of single-crystal silicon, thereby reducing the surface roughness of the workpiece.

Electronic Properties of Femtosecond Laser Induced Modified Spots on Single Crystal Silicon Carbide

2010 ◽  
Vol 645-648 ◽  
pp. 239-242 ◽  
Author(s):  
Takuro Tomita ◽  
M. Iwami ◽  
M. Yamamoto ◽  
M. Deki ◽  
Shigeki Matsuo ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Femtosecond Laser ◽  
Single Crystal ◽  
Specific Resistance ◽  
Single Crystal Silicon ◽  
Metal Contacts ◽  
Crystal Silicon ◽  
Current Voltage ◽  
Fs Laser ◽  
Current Voltage Characteristics

Femtosecond (fs) laser modification on single crystal silicon carbide (SiC) was studied from the viewpoints of electric conductivity. Fourier transform infrared (FTIR) spectroscopy was carried out on femtosecond laser modified area. The intensity decrease of reststrahlen band due to the modification was observed, and this decrease was explained by the degradation of crystallinity due to the laser irradiation. Polarization dependence of reststrahlen band was also observed on laser modified samples. Current-voltage characteristics and Hall measurements on fs-laser modified region were carried out by fabricating the metal contacts on the ion implanted areas. The specific resistance up to 5.9×10-2 m was obtained for fs-laser modified area.

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