Quasi-two-dimensionalβ-Ga2O3 field effect transistors with large drain current density and low contact resistance via controlled formation of interfacial oxygen vacancies  

作　　者：Zhen Li Yihang Liu Anyi Zhang Qingzhou Liu Chenfei Shen Fanqi Wu Chi Xu Mingrui Chen Hongyu Fu Chongwu Zhou 

机构地区：[1]Ming Hsieh Department of Electrical Engineering,Mork Family Department of Chemical Engineering and Material Science,Department of Physics and Astronomy,University of Southern CalifomiOy Los Angeles,California 90089,USA

出　　处：《Nano Research》2019年第1期143-148,共6页纳米研究（英文版）

摘　　要：Quasi-two-dimensi on al(2D)β-Ga2O3 is a rediscovered metal-oxide semiconductor with an ultra-wide bandgap of 4.6-4.9eV.It has been reported to be a promising material for next-generation power and radio frequency electronics.Field effect transistors(FETs)that can switch at high voltage are key compone nts in power and radio frequency devices,and reliable Ohmic con tacts are essential for high FET performance.However,obtaining low contact resistance onβ-Ga2O3 FETs is difficult since reactions betweenβ-Ga2O3 and metal contacts are not fully understood.Herein,we experimentally demonstrate the importanee of reactions at the metal/β-Ga2O3 interface and the corresponding effects of these reactions on FET performance.When Ti is employed as the metal contact,annealing ofβ-Ga2O3 FETs in argon can effectively transform Schottky contacts into Ohmic contacts and permit a large drain current density of-3.1 mA//μm.The contact resistance(Rcontact)between the Ti electrodes andβ-Ga2O3 decreased from^430 to^0.387Ω·mm after annealing.X-ray photoelectron spectroscopy(XPS)confirmed the formation of oxygen vacancies at the Ti/β-Ga2O3 interface after annealing,which is believed to cause the improved FET performance.The results of this study pave the way for greater application ofβ-Ga2O3 in electronics.

关 键 词：quasi-two-dimensional material METAL-OXIDES field effect TRANSISTOR β-Ga2O3 contact resistanee 

分 类 号：O78[理学—晶体学]