Abstract:Al-doped ZnO (AZO) target was prepared by hot pressing using ZnO and Al₂O₃ powder in mass ratio of 98:2. The effects of hot pressing conditions including temperature, pressure and preserving time on relative density were investigated. Pore evolution and phase structure change during densification process were studied. The results show that AZO target with super high relative density of 99% was prepared by two-stage hot pressing method under pressure of 35 MPa, temperature of 1 050 °C and 1 150 °C with preserving time of 1 h, respectively. At temperature around 1 050 °C, the number of isolated pore was minimum. At temperature lower than 900 °C, there existed Al₂O₃ phase. At temperature higher than 1 000 °C, ZnAl₂O₄ phase was generated and its content was increased with temperature increasing. Hot pressing method had the advantage over pressureless sintering that the content of ZnAl₂O₄ was lower and sintering temperature could be also lower. With increasing the hot pressing temperature and preserving time, the electric resistivity of AZO target decreased greatly. A low resistivity of 3´10^{−3 W}×cm was achieved under the temperature of 1 100 °C, pressure of 35 MPa and preserving time of 10 h.

Key words: aluminum-doped ZnO (AZO); sputter target; hot pressing; pore; phase structure