Electrical performance of Al2O3 gate dielectric films deposited by atomic layer deposition on 4H-SiC
Electrical performance of Al2O3 gate dielectric films deposited by atomic layer deposition on 4H-SiC
复制标题
DOI：
10.1063/1.2805742
复制
发表时间：
2007-11-12
影响因子：
4
通讯作者：
Chang, Jane P.
中科院分区：
文献类型：
--
作者：
Tanner, Carey M.;Perng, Ya-Chuan;Chang, Jane P.
采用热原子层沉积法在n型4 H-SiC衬底上制备了化学计量比的纯Al 2 O3栅介质膜。通过测量金属氧化物半导体电容器的电容-电压和电流-电压，研究了非晶和外延Al 2 O3薄膜的电学性质。确定了介电常数为9，平带电压漂移为+1.3 V。在8 MV/cm时，非晶Al_2 O_3膜的漏电流密度为10（-3）A/cm（2），低于迄今报道的任何4 H-SiC上的高k栅氧化物的漏电流密度。使用Fowler-Nordheim隧穿机制来确定1.58 eV的Al 2 O3/4 H-SiC势垒高度。较高的漏电流获得的外延γ-Al 2 O 3膜，可能是由于晶界传导。(c)2007年，美国物理学会。
Stoichiometric and pure Al2O3 gate dielectric films were grown on n-type 4H-SiC by a thermal atomic layer deposition process. The electrical properties of both amorphous and epitaxial Al2O3 films were studied by capacitance-voltage and current-voltage measurements of metal-oxide-semiconductor capacitors. A dielectric constant of 9 and a flatband voltage shift of +1.3 V were determined. A leakage current density of 10(-3) A/cm(2) at 8 MV/cm was obtained for the amorphous Al2O3 films, lower than that of any high-kappa gate oxide on 4H-SiC reported to date. A Fowler-Nordheim tunneling mechanism was used to determine an Al2O3/4H-SiC barrier height of 1.58 eV. Higher leakage current was obtained for the epitaxial gamma-Al2O3 films, likely due to grain boundary conduction. (c) 2007 American Institute of Physics.