AlInN三明治势垒GaN HFET

GaN HFET with AlInN Sandwich Barrier

介绍了国际上AlInN势垒HFET的最新发展。从器件性能分析中发现这种新势垒显著提高了沟道电子气密度,增大了强场漂移速度,消除应变提高了器件可靠性和热稳定性,能在高温下有效工作,使GaN HFET研究走上新的台阶。但是薄势垒引起的大栅流和电流崩塌是阻碍器件性能提高和实际应用的主要瓶颈。利用AlInN/AlGaN异质界面的大能带带阶和强极化电荷来剪裁能带,设计出新的三明治势垒,满足内、外沟道和欧姆接触势垒的要求。可望消除上述瓶颈,使AlInN势垒GaN HFET付诸实用。

The international recent development of GaN HFET with AlInN barrier is introduced in this paper.It is found from the analysis of recent device performances that thanks to the new barrier,the electron density in channel has been increased extremely,the electron drift velocity under strong electric field has been enhanced,and the device reliability and hot stability has been improved through the weakening of crystal strain,which makes the new HFET may be applied in high temperature environment really and truly.However,the large gate leakage current and current collapse induced by the thin barrier result in a serious bottleneck to prevent the new devices from practical application.The large band offset and strong polar charge at the interface of AlInN/GaN heterojunction has been used to tailor the band structure of channel well in this paper,from which a new sandwich barrier satisfying different demands of the ohmic contact,the inner channel barrier,and the outer channel barrier respectively is devised.It had hoped that the mentioned bottleneck may be canceled by this sandwich barrier to enable the AlInN/GaN devices to meet requirements for various applications.