Abstract
High k dielectrics, such as Al2O3, has attracted increasing research attention for its use as the gate dielectric of 4H-SiC MOS capacitors. Since the dielectric constant of Al2O3 is not high enough, many other high-k dielectrics are actively explored. In this letter, a report of the interface properties of 4H-SiC MOS capacitors with Hafnium silicate (HfSiOx) dielectric is presented. The HfSiOx dielectric was deposited by thermal atomic layer deposition. A systematic study of I-V and multi-frequency C-V characteristics were carried out and the results showed HfSiOx gate dielectric could effectively increase dielectric constant. A thin layer of SiO2 in between SiC and high k dielectric can further improve interface properties. These results indicate that HfSiOx could be a promising candidate as suitable gate dielectric material for future 4H-SiC MOS capacitors and MOSFETs.
Highlights
Silicon carbide (SiC) is a wide bandgap semiconductor which holds great promise for nextgeneration power devices
Since the dielectric constant of SiC is much higher than that of SiO2, the electric field in SiO2 is always much higher than that of SiC, especially when it reaches the critical field of SiC at 3 MV/cm, which will lead to a severe reliability problem for the SiO2 dielectrics.[2]
High k dielectrics can be applied on SiC to alleviate the electric field in the gate dielectric[1] and some example high k materials are Al2O3,3,4 HfO2,5–7 AlON8 and La2O3.9,10 A study with Al2O3 as the gate dielectrics was taken and it showed using Al2O3 could increase the dielectric constant, improving the stabilities of the gate dielectric of SiC MOS capacitors.[11]
Summary
Silicon carbide (SiC) is a wide bandgap semiconductor which holds great promise for nextgeneration power devices. Lin Liang,[1] Wei Li,[2] Sichao Li,[1] Xuefei Li,[1] and Yanqing Wu1,a 1State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China 2School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China (Received 10 August 2018; accepted 16 November 2018; published online 6 December 2018)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
