Interfacial and electrical characteristics of a HfO2/n–InAlAs MOS-capacitor with different dielectric thicknesses

• Published in: 中国物理B：英文版 no. 12; pp. 460 - 464
• Main Author: 关赫 吕红亮 郭辉 张义门 张玉明 武利翻
• Format: Journal Article
• Language: English
• Published: 01.12.2015
• Subjects: HEMT器件; InAlAs; MOS电容器; 介电层; 使用界面; 氧化铪; 电气特性; 等效介电常数
• ISSN: 1674-1056; 2058-3834
• DOI: 10.1088/1674-1056/24/12/126701

AHfO2/n–In Al As MOS-capacitor has the advantage of reducing the serious gate leakage current when it is adopted in In As/Al Sb HEMT instead of the conventional Schottky-gate. In this paper, three kinds of Hf O2/n–InAlAs MOS-capacitor samples with different Hf O2 thickness values of 6, 8, and 10 nm are fabricated and used to investigate the interfacial and electrical characteristics. As the thickness is increased, the equivalent dielectric constant ε ox of Hf O2 layer is enhanced and the In AlAsHfO2 interface trap density Ditis reduced, leading to an effective reduction of the leakage current. It is found that the Hf O2 thickness of 10 nm is a suitable value to satisfy the demands of most applications of a HfO2/n–InAlAs MOS-capacitor, with a sufficiently low leakage current compromised with the threshold voltage.