Doping Effect on Characteristics of Al2O3 Ceramics for Glass Substrate Electrostatic Chucking

Highly resistive Al2O3 ceramics have been widely used for electrostatic chucking of silicon wafer. However, there are some restrictions to use such chuck material on higher resistance substrates, such as glass or sapphire wafer. In this study, Al2O3 compositions were modified by various dopants; TiO2, CuO and SiO2, and their sinterability, crystal structure, electrical properties and chucking property were investigated with different doping concentrations and sintering conditions. Both of TiO2 and CuO were found to be key dopants on controlling the sintering temperature and electrical resistivity. When 2 similar to 3 mol% of TiO2 and CuO, and 1mol% of SiO2 were added simultaneously, the specimens having lowered resistivity, similar to 10(12) Omega cm were obtained at a relatively lowered sintering temperature, 1250 degrees C, which means that the electrostatic chuck for display and LED-sapphire chip processes can be economically fabricated by using simple ceramic process.