Highly Sensitive Detection of Deoxyribonucleic Acid Hybridization Using Au-Gated AlInN/GaN High Electron Mobility Transistor-Based Sensors

Gallium nitride- （GaN） based high electron mobility transistors （HEMTs） provide a good platform for biological detection. In this work, both Au-gated AlInN/GaN HEMT and AlGaN/GaN HEMT biosensors are fabricated for the detection of deoxyribonucleic acid （DNA） hybridization. The Au-gated AIInN/GaN HEMT biosensor exhibits higher sensitivity in comparison with the AlGaN/GaN HEMT biosensor. For the former, the drain-source current （VDS = 0.5 V） shows a clear decrease of 69μA upon the introduction of 1μmolL^-1 （μM） complimentary DNA to the probe DNA at the sensor area, while for the latter it is only 38 μA. This current reduction is a notable indication of the hybridization. The high sensitivity can be attributed to the thinner barrier of the AlInN/GaN heterostructure, which makes the two-dimensional electron gas channel more susceptible to a slight change of the surface charge.

AlInN三明治势垒GaN HFET

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。