Surface Lapping Process and Vickers Indentation of Sapphire Wafer for GaN Epitaxy

GaN 증착용 사파이어 웨이퍼의 표면가공에 따른 압흔 특성

  • Published : 2005.04.01


The surface lapping process on sapphire wafer was carried out for the epitaxial process of thin film growth of GaN semiconducting material. The planarization of the wafers was investigated by the introduction of the dummy wafers. The diamond lapping process causes the surface deformation of dislocation and micro-cracks. The material deformation due to the mechanical stress was analyzed by the X-ray diffraction and the Vickers indentation. The fracture toughness was increased with the increased annealing temperature indicating the recrystallization at the surface of the sapphire wafer The sudden increase at the temperature of $1200^{\circ}C$ was correlated with the surface phase transition of sapphire from a $-A1_{2}O_{3}\;to\;{\beta}-A1_{2}O_{3}$.


Blue-LED Sapphire Wafer;Thermal Annealing;Indentation;Recrystallization;FWHM


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