Development of AlN/Diamond Heterojunction Field Effect Transistor

改善了AlN/金刚石异质结p沟道FET的器件特性，并对其工作机理进行了研究。采用金属有机气相外延技术在金刚石衬底上生长了氮化铝。由于在源漏电极下方用Cl2气体刻蚀AlN，并采用PD作为欧姆接触，FET的性能得到了显著提高。在H2和NH3混合气氛中对金刚石表面进行1250oC的热处理，获得了与金刚石基片结合良好的AlN，同时也获得了表面空穴载体。根据场效应管具有常导型的特点，认为AlN作为保护层和绝缘层。

The device properties of AlN/diamond heterojunction p-channel FET were improved and the operation mechanism of this FET was investigated. AlN was grown on diamond substrates using metalorganic vapor phase epitaxy. Owing to the etching of AlN just below the source-drain electrodes by Cl2 gas and the adopting the Pd for ohmic contacts, the FET performance was drastically improved. The thermal treatment (1250 oC) in the mixed H2 and NH3 atmosphere for oxygen-terminated diamond surface produced the AlN with good adhesion to diamond substrates and the surface hole-carrier at the same time. Judged from the fact that the FET had a normally-on mode, AlN was considered to be worked as the protection and insulating layer.