Metal dopants in HfO_2-based RRAM: first principle study  

作　　者：赵远洋 汪家余 徐建彬 杨菲 刘琦 代月花 

机构地区：[1]Institute of Electronic and Information Project, Anhui University [2]Laboratory of Nano-Fabrication and Novel Device Integrated Technology,Institute of Microelectronics, Chinese Academyof Sciences

出　　处：《Journal of Semiconductors》2014年第4期25-31,共7页半导体学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.61376106)

摘　　要：Based on density-functional theory （DFT）, the effects of metal dopants in HfO2-based RRAM are studied by the Vienna ab initio simulation package （VASP）, Metal dopants are classified into two types （interstitial and substitutional） according to the formation energy when they exist in HfO2 cell. Several conductive channels are observed through the isosurface plots of the partial charge density for HfO2 doped with interstitial metals, while this phenomenon cannot be found in HfO2 doped with substitutional metals. The electron density of states （DOS） and the projected electron density of states （PDOS） are calculated and analyzed; it is found that the conduction filament in HfO2 is directly formed by the interstitial metals and further, that the substitutional metals cannot directly generate conduction filament. However, all the metal dopants contribute to the formation of the oxygen vacancy （Vo） filament. The formation energy of the Vo and the interaction between metal dopants and Vo are calculated; it is revealed that the P-type substitutional metal dopants have a strong enhanced effect on the Vo filament, the interstitial metal dopants have a minor assistant effect, while Hf-like and N-Woe substitutional metal dopants have the weakest assistant effect.Based on density-functional theory （DFT）, the effects of metal dopants in HfO2-based RRAM are studied by the Vienna ab initio simulation package （VASP）, Metal dopants are classified into two types （interstitial and substitutional） according to the formation energy when they exist in HfO2 cell. Several conductive channels are observed through the isosurface plots of the partial charge density for HfO2 doped with interstitial metals, while this phenomenon cannot be found in HfO2 doped with substitutional metals. The electron density of states （DOS） and the projected electron density of states （PDOS） are calculated and analyzed; it is found that the conduction filament in HfO2 is directly formed by the interstitial metals and further, that the substitutional metals cannot directly generate conduction filament. However, all the metal dopants contribute to the formation of the oxygen vacancy （Vo） filament. The formation energy of the Vo and the interaction between metal dopants and Vo are calculated; it is revealed that the P-type substitutional metal dopants have a strong enhanced effect on the Vo filament, the interstitial metal dopants have a minor assistant effect, while Hf-like and N-Woe substitutional metal dopants have the weakest assistant effect.

关 键 词：RRAM metal dopant conduction filament INTERSTITIAL SUBSTITUTIONAL 

分 类 号：TP333[自动化与计算机技术—计算机系统结构]