• Korean Journal of Materials Research
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• v.25 no.1
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• pp.21-26
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• 2015

CMP(Chemical Mechanical Polishing) Processes have been used to improve the planarization of the wafers in the semiconductor manufacturing industry. Polishing performance of CMP Process is determined by the chemical reaction of the liquid sol containing abrasive, pressure of the head portion and rotational speed of the polishing pad. However, frictional heat generated during the CMP process causes agglomeration of the particles and the liquidity degradation, resulting in a non-uniform of surface roughness and surface scratch. To overcome this chronic problem, herein, we introduced NaCl salt as an additive into silica sol for elimination the generation of frictional heat. The added NaCl reduced the zata potential of silica sol and increased the contact surface of silica particles onto the sapphire wafer, resulting in increase of the removal rate up to 17 %. Additionally, it seems that the silica particles adsorbed on the polishing pad decreased the contact area between the sapphire water and polishing pad, which suppressed the generation of frictional heat.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.34 no.4
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• pp.139-142
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• 2024

Along with the use of wide bandgap energy materials such as SiC and GaN in power semiconductors and the development trend of devices, many research results have been reported, including the success of research on AlN single crystals with higher energy gaps and the development of 2-inch single crystal wafers. However, AlN single crystals grown using chemical vapor deposition have been developed into thin films less than a few micrometers thick, but there are almost no results with thicknesses greater than that. Therefore, in this study, we attempted to grow by applying HVPE (Hydride vapor phase epitaxy), one of the chemical vapor deposition methods. The grown AlN single crystal was manufactured using self-designed equipment, and we attempted to establish the conditions for manufacturing AlN single crystals on sapphire wafer. We would like to characterize the growth behavior through an optical microscope observation.