Investigation of charge loss characteristics of HfO_2 annealed in N_2 or O_2 ambient

作     者：褚玉琼 霍宗亮 韩宇龙 陈国星 张冬 李新开 刘明 

作者机构：Laboratory of Nano-Fabrication and Novel Devices Integrated Technology Institute of Microelectronics Chinese Academy of Sciences 

出 版 物：《Journal of Semiconductors》 (半导体学报（英文版）)

年 卷 期：2014年第35卷第8期

页      面：43-47页

核心收录：

学科分类：08[工学] 081201[工学-计算机系统结构] 0812[工学-计算机科学与技术（可授工学、理学学位）] 

基　　金：Project supported by the MOST(Nos.2010CB934200,2011CBA00600) the National Natural Science Foundation of China(No.61176073) 

主　　题：KFM Hf02 retention 

摘      要：The retention characteristics of electrons and holes in hafnium oxide with post-deposition annealing in a N2 or 02 ambient were investigated by Kelvin probe force microscopy. The KFM results show that compared with the N2 PDA process, the O2 PDA process can lead to a significant retention improvement. Vertical charge leakage and lateral charge spreading both played an important role in the charge loss mechanisms. The retention improvement is attributed to the deeper trap energy. For electrons, the trap energy of the HOS structure annealed in a N2 or 02 ambient were determined to be about 0.44 and 0.49 eV, respectively. For holes, these are about 0.34 and 0.36 eV, respectively. Finally, the electrical characteristics of the memory devices are demonstrated from the experiment, which agreed with our characterization results. The qualitative and quantitative determination of the charge retention properties, the possible charge decay mechanism and trap energy reported in this work can be very useful for the characterization of hafnium charge storage devices.