脉冲激光沉积制备的HfO2薄膜的结构与电学性能

Structure and electric properties of HfO2 films prepared by pulsed laser deposition

采用脉冲激光沉积（PLD）方法在Si（100）基底上制备了有效氧化层厚度为8．6nm，介电常数为29．3的HfO2薄膜．借助C射线衍射（XRD）、原子力显微镜（AFM）、高分辨透射电镜（HRTEM）分析了样品的微观结构，对电容的C-V与I-V电学特性进行了测试。实验结果表明，该方法制得的HfO2薄膜表面光滑，N2500℃下退火30mm后样品表面粗糙度由0．203nm变为0．498nm，薄膜由非晶转变为简单正交结构，界面层得到有效控制，该栅介质电容具有良好的C-V特性，较低的漏电流密度（4．3×10^-7A/cm^2，@-1V），是SiO2栅介质的理想替代物．

High-K gate dielectric hafnium dioxide films were grown on Si （100） substrate by pulsed laser deposition at room temperature. Their micro-structure and electrical properties were characterized by X-ray diffraction, atomic force microscopy, high-resolution transmission electron microscopy and capacitance-voltage and current-voltage measurements using Pt electrodes. The result indicates that as-deposited HfO2 films are amorphous and a transition to orthorhombic after annealing in N2. The electrical properties were characterized by capacitance-voltage and current-voltage measurements using Pt electrodes. High quality HfO2 gate dielectric thin films with smooth surface which root mean square roughness of 0.498nm, equivalent oxide thickness （EOT） of 8.6nm, high dielectric constant （29.3）, and low leakage current density of 4.3×10^-7A/cm^2 at bias voltage 1.5V has been obtained.