不同退火氛围对TiN/HfO_(2)/SiO_(2)/Si结构电荷分布的影响  

Effects of Different Annealing Atmosphere on Charge Distribution of TiN/HfO_(2)/SiO_(2)/Si Structure

作　　者：徐永贵[1] 韩锴[1] 高建峰[2] Xu Yonggui;Han Kai;Gao Jianfeng(Department of Physics and Optoelectronic Engirteering,weifang University,Weifang 261061,China;Institute of Microelectronics,Chinese Academy of Sciences,Beijing 100029,China)

机构地区：[1]潍坊学院物理与光电工程学院,山东潍坊261061 [2]中国科学院微电子研究所,北京100029

出　　处：《半导体技术》2021年第1期64-69,共6页Semiconductor Technology

基　　金：国家自然科学基金资助项目(61674003);国家科技重大专项资助项目(2017ZX02301007-001)。

摘　　要：热退火技术是集成电路制造过程中用来改善材料性能的重要手段。系统分析了两种不同的退火条件(氨气氛围和氧气氛围)对TiN/HfO_(2)/SiO_(2)/Si结构中电荷分布的影响,给出了不同退火条件下SiO_(2)/Si和HfO_(2)/SiO_(2)界面的界面电荷密度、HfO_(2)的体电荷密度以及HfO_(2)/SiO_(2)界面的界面偶极子的数值。研究结果表明,在氨气和氧气氛围中退火会使HfO_(2)/SiO_(2)界面的界面电荷密度减小、界面偶极子增加,而SiO_(2)/Si界面的界面电荷密度几乎不受退火影响。最后研究了不同退火氛围对电容平带电压的影响,发现两种不同的退火条件都会导致TiN/HfO_(2)/SiO_(2)/Si电容结构平带电压的正向漂移,基于退火对其电荷分布的影响研究,此正向漂移主要来源于退火导致的HfO_(2)/SiO_(2)界面的界面偶极子的增加。Thermal annealing technology is an important method to improve material properties in the integrated circuit manufacturing process.The effects of two different annealing conditions(ammonia atmosphere and oxygen atmosphere)on the charge distribution of the TiN/HfO_(2)/SiO_(2)/Si structure were systematically analyzed.The interface charge densities of the SiO_(2)/Si and HfO_(2)/SiO_(2) interfaces,the bulk charge density of HfO_(2) and the value of the interface dipole at the HfO_(2)/SiO_(2) interface were given under different annealing conditions.The research results show that the interface charge density of HfO_(2)/SiO_(2) interface decreases and the interface dipole increases,while the interface charge density of SiO_(2)/Si interface is hardly affected by annealing in ammonia atmosphere and oxygen atmosphere.Finally,the effect of different annealing atmospheres on the flat-band voltage of the capacitor was studied.It is found that two different annealing conditions lead to the positive shift of the flat-band voltage of the TiN/HfO_(2)/SiO_(2)/Si capacitor structure.Based on the study of the effect of annealing on its charge distribution,the positive shift of the flat-band voltage is mainly due to the increase of interface dipoles at the HfO_(2)/SiO_(2) interface caused by annealing.

关 键 词：高K栅介质 金属栅 退火 电荷分布 偶极子 

分 类 号：TN305[电子电信—物理电子学] TN301