Survey on the Progress of Ultra-smooth Sapphire Wafer Surface

This paper review the status,technology and progress of sapphire wafer for blue LED.The applications status of sapphire wafer in ultra-smooth process were presented.The applications on sapphire wafer by grinding,mechanical polishing,dry mechanochemical polishing,wet mechanochemical polishing and chemical mechanical polishing were analyzed.Comparison on damage characteristics,strongpoints and defects of machining sapphire wafer by different methods were made.