%A He Guan(关赫), Cheng-Yu Jiang(姜成语), Shao-Xi Wang(王少熙)
%T Effect of annealing temperature on interfacial and electrical performance of Au-Pt-Ti/HfAlO/InAlAs metal-oxide-semiconductor capacitor
%0 Journal Article
%D 2020
%J Chin. Phys. B
%R 10.1088/1674-1056/ab8a34
%P 96701-096701
%V 29
%N 9
%U {https://cpb.iphy.ac.cn/CN/abstract/article_122771.shtml}
%8 2020-09-05
%X HfAlO/InAlAs metal-oxide-semiconductor capacitor (MOS capacitor) is considered as the most popular candidate of the isolated gate of InAs/AlSb high electron mobility transistor (HEMT). In order to improve the performance of the HfAlO/InAlAs MOS-capacitor, samples are annealed at different temperatures for investigating the HfAlO/InAlAs interfacial characyeristics and the device's electrical characteristics. We find that as annealing temperature increases from 280 ℃ to 480 ℃, the surface roughness on the oxide layer is improved. A maximum equivalent dielectric constant of 8.47, a minimum equivalent oxide thickness of 5.53 nm, and a small threshold voltage of -1.05 V are detected when being annealed at 380 ℃; furthermore, a low interfacial state density is yielded at 380 ℃, and this can effectively reduce the device leakage current density to a significantly low value of 1×10-7 A/cm2 at 3-V bias voltage. Therefore, we hold that 380 ℃ is the best compromised annealing temperature to ensure that the device performance is improved effectively. This study provides a reliable conceptual basis for preparing and applying HfAlO/InAlAs MOS-capacitor as the isolated gate on InAs/AlSb HEMT devices.