Effects of substrate heating and post-deposition annealing on characteristics of thin MOCVD HfO2 films

International Conference on Advances in Materials and Manufacturing Applications 2017

Gopalan, Sundararaman^1 ; Ramesh, Sivaramakrishnan^2 ; Dutta, Shibesh^2 ; Virajit Garbhapu, Venkata^1

Department of Electronics and Communication Engineering, Amrita School of Engineering, Amritapuri, Amrita Vishwa Vidyapeetham, Amrita University, India^1

IMEC, Leuven

B-3001, Belgium^2

关键词: Electrical characteristic;    Hf-based dielectrics;    High-k materials;    Memory applications;    Oxygen flow rates;    Post deposition annealing;    Substrate heating;    Substrate temperature;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/310/1/012125/pdf
DOI  :  10.1088/1757-899X/310/1/012125

来源: IOP

【 摘 要 】

It is well known that Hf-based dielectrics have replaced the traditional SiO2and SiON as gate dielectric materials for conventional CMOS devices. By using thicker high-k materials such as HfO2rather than ultra-thin SiO2, we can bring down leakage current densities in MOS devices to acceptable levels. HfO2is also one of the potential candidates as a blocking dielectric for Flash memory applications for the same reason. In this study, effects of substrate heating and oxygen flow rate while depositing HfO2thin films using CVD and effects of post deposition annealing on the physical and electrical characteristics of HfO2thin films are presented. It was observed that substrate heating during deposition helps improve the density and electrical characteristics of the films. At higher substrate temperature, Vfbmoved closer to zero and also resulted in significant reduction in hysteresis. Higher O2flow rates may improve capacitance, but also results in slightly higher leakage. The effect of PDA depended on film thickness and O2PDA improved characteristics only for thick films. For thinner films forming gas anneal resulted in better electrical characteristics.