Gd_2O_3-HfO_2栅介质薄膜的外延制备及Ge-MOS电学特性分析  

Fabrication and Electronic Characterization of Epitaxial Gd_2O_3-Doped HfO_2 Dielectrics on Ge Substrates

作　　者：张心强[1] 屠海令[1,2] 杜军[1,2] 杨萌萌[1] 赵鸿滨[1] 杨志民[1] 

机构地区：[1]北京有色金属研究总院先进电子材料研究所,北京100088 [2]北京有色金属研究总院国家半导体材料工程技术研究中心,北京100088

出　　处：《稀有金属》2012年第3期405-409,共5页Chinese Journal of Rare Metals

基　　金：国家自然科学基金重点基金(50932001);国家自然科学基金青年科学基金(51102020);国家自然科学基金委员会和中国工程物理研究院联合基金资助项目(11076005);国家重大科技专项02专项(2009ZX02039-005)

摘　　要：以Gd2O3-HfO2(GDH)固溶氧化物作为靶材,采用脉冲激光沉积技术(PLD)在Ge(100)衬底上制备了GDH高k栅介质外延薄膜,其外延生长方式为"cube-on-cube",GDH薄膜与Ge(100)衬底的取向关系为(100)GDH∥(100)Ge和[110]GDH∥[110]Ge。通过反射式高能电子衍射(RHEED)技术研究了激光烧蚀能量和薄膜沉积温度对薄膜晶体结构的影响,分析了二者与薄膜的取向关系,激光烧蚀能量对薄膜取向影响更为显著。得到较优的GDH外延薄膜沉积工艺为:激光烧蚀能量为3 J·cm-2、薄膜的沉积温度为600℃。用磁控溅射制备了Au/Ti顶电极和Al背电极,其中圆形的Au/Ti电极通过掩膜方法获得,直径为50μm。采用Keithley 4200半导体测试仪对所制备Au/Ti/GDH/Ge/Al堆栈结构的Ge-MOS原型电容器进行电学特性分析,测试条件为:I-E测试的电场强度0～6 MV·cm-1,C-V测试的频率300 kHz～1 MHz,结果表明,厚度为5 nm的GDH薄膜具备良好介电性能:k～28,EOT～0.49 nm,适于22 nm及以下技术节点集成电路的应用。The HfO2 doped with Gd2O3（GDH） films as high k dielectrics were epitaxially grown on Ge（100） substrates by pulsed laser deposition（PLD）.Epitaxial growth adopted in a cube-on-cube mode.Evolution of the（100）-oriented GDH films during the deposition was in situ investigated by reflection high-energy electron diffraction（RHEED）.The in-plane orientation relationship between（100） GDH film and（100） Ge substrate was（100） GDH∥（100）Ge and GDH∥Ge.Appropriate preparation conditions of epitaxial GDH films were as follows： laser ablation energy of 3 J · cm-2,deposition temperature of 600℃.Compared with the effects of deposition temperature on the epitaxial growth of GDH on Ge,that of laser ablation energy was much more evident.Au electrodes and Al electrodes were prepared by radio frequency magnetron sputtering,and Au top electrodes with diameter of 50 μm were obtained through mask method.The electrical characters of Ge-MOS capacitors were tested by Keithley 4200,and the results showed good dielectric properties of GDH films,such as high dielectric constant（~28） and low equivalent oxide thickness（EOT^0.49） at E of 0~6 MV · cm-1 and measurement frequency of 300 kHz^1 MHz.The experimental finding indicated that the epitaxial stack of GDH/Ge was suited for application to 22 nm technology node and beyond.

关 键 词：GD2O3 HFO2 Ge 外延 激光脉冲沉积 高k 

分 类 号：TN386.1[电子电信—物理电子学]