摘要
The N_(2)O radicals in-situ treatment on gate region has been employed to improve device performance of recessedgate Al Ga N/Ga N high-electron-mobility transistors(HEMTs).The samples after gate recess etching were treated by N_(2)O radicals without physical bombardment.After in-situ treatment(IST)processing,the gate leakage currents decreased by more than one order of magnitude compared to the sample without IST.The fabricated HEMTs with the IST process show a low reverse gate current of 10;A/mm,high on/off current ratio of 108,and high f_(T)×L_(g)of 13.44 GHz·μm.A transmission electron microscope(TEM)imaging illustrates an oxide layer with a thickness of 1.8 nm exists at the AlGaN surface.X-ray photoelectron spectroscopy(XPS)measurement shows that the content of the Al-O and Ga-O bonds elevated after IST,indicating that the Al-N and Ga-N bonds on the AlGaN surface were broken and meanwhile the Al-O and Ga-O bonds formed.The oxide formed by a chemical reaction between radicals and the surface of the AlGaN barrier layer is responsible for improved device characteristics.
基金
Project supported by the National Key Research and Development Program of China(Grant No.2018YFB1802100)
the National Natural Science Foundation of China(Grant Nos.62104184,62090014,62104178,and 62104179)
the Fundamental Research Funds for the Central Universities of China(Grant Nos.XJS201102,XJS211101,XJS211106,and ZDRC2002)
the Natural Science Foundation of Shaanxi Province,China(Grant Nos.2020JM-191 and 2018HJCG-20)。
