高介电常数的栅极电介质LaAlO_3薄膜的性能研究  

Properties of High-k Gate Dielectric LaAlO_3 Thin Films

作　　者：王东生[1] 于涛[1] 游彪[1] 夏奕东[1] 胡安[1] 刘治国[1] 

机构地区：[1]南京大学固体微结构物理国家重点实验室,南京210093

出　　处：《无机材料学报》2003年第1期229-232,共4页Journal of Inorganic Materials

基　　金：国家自然科学基金(19890310)

摘　　要：在室温下,采用射频磁控溅射法在Si衬底上制备了具有高介电常数的LaAlO3薄膜,这是一种新的栅极电介质材料.在高纯O2中经过15min650℃的高温退火后LaAlO3薄膜仍然不晶化,这种热稳定性有利于减小薄膜的漏电流.本工作研究了LaAlO3薄膜的介电性能,其电容等效氧化物厚度为2.33nm,在外加偏压±1V处的漏电流很低,分别为3.73mA/cm2(+1V处)和5.32×10-4mA/cm2(-1V处),两者相差四个数量级.此结果表明,Pt/LaAlO3/Si结构具有良好的单向导电性能. C-V曲线的滞后电压VH=0.09V,界面态密度的值约为8.35×1011cm-2.研究结果表明,在今后的半导体器件的甚大规模集成(ULSI)中,具有高介电常数的LaAlO3薄膜将会是一种极有希望的栅极电介质材料.The properties of a new high-k gate dielectric material LaAlO3 were investigated. LaAlO3 thin films were prepared on p-type Si substrates by using radio-frequency magnetron sputtering deposition. XRD analyses show that the films are amorphous even after annealed in O2 at 650℃ for 15min. The capacitance equivalent oxide thickness is 2.33nm with a leakage current of 3.73mA/cm2 and 5.32×10-4mA/cm2 at Vg=4+1V and -1V, respectively. The capacitance-voltage (C-V) characteristic curves show the existence of interface states in LaAlOs thin films. The hysteresis voltage in C - V curve is about 0.09V. The density of interface states calculated is about 8.35×1011cm-2. The current-voltage characteristic curves show that Pt/LaAlO3/Si thin film is conductive only under one voltage direction. The LaAlO3 thin film will be a promising high-fc gate dielectric for future ultra-large scale integrated devices.

关 键 词：栅极电介质材料 介电常数 LaAlO3薄膜 铝酸镧 半导体集成电路 

分 类 号：TN4[电子电信—微电子学与固体电子学] TM215[一般工业技术—材料科学与工程]