This paper focuses on how to reduce the gate leakage current caused by plasma dry etching. X-ray photoelectron spectroscopy （XPS） is employed to measure the AlGaN surface before and after etching. N vacancies are in...This paper focuses on how to reduce the gate leakage current caused by plasma dry etching. X-ray photoelectron spectroscopy （XPS） is employed to measure the AlGaN surface before and after etching. N vacancies are introduced, which cause that gate currents are not dominated by the thermal electron emission mechanism. N vacancies enhance the tunneling effect and reduce the Schottky barrier height as n-type doped in the etched AIGaN surface.A post-gate process for AlGaN/GaN HEMTs,annealing at 400℃ in a nitrogen ambient for 10min is introduced. After annealing, Ni atoms of gate metal reacted with Ga atoms of AlGaN, and N vacancies were reduced. The reverse leakage decreased by three orders of magnitude,the forward turn-on voltage increased and the ideality factor reduced from 3.07 to 2.08.展开更多
Nano-hole patterned sapphire substrates （NHPSSs） were successfully prepared using a low-cost and high-efficiency approach, which is the laser interference lithography （LIL） combined with reactive ion etching （RIE...Nano-hole patterned sapphire substrates （NHPSSs） were successfully prepared using a low-cost and high-efficiency approach, which is the laser interference lithography （LIL） combined with reactive ion etching （RIE） and inductively coupled plasma （ICP） techniques. Gallium nitride （GaN）-based light emitting diode （LED） structure was grown on NHPSS by metal organic chemical vapor deposition （MOCVD）. Photoluminescence （PL） measurement was conducted to compare the luminescence efficiency of the GaN-based LED structure grown on NHPSS （＇NHPSS-LED） and that on unpatterned sapphire substrates （UPSS-LED）. Electroluminescence （EL） measurement shows that the output power of NHPSS-LED is 2.3 times as high as that of UPSS-LED with an injection current of 150 mA. Both PL and EL results imply that NHPSS has an advantage in improving the crystalline quality of Gab/epilayer and light extraction efficiency of LEDs at the same time.展开更多
基金supported by the State Key Development Programfor Basic Research of China(No.2002CB311903)the Key Innovation Program of the Chinese Academy of Sciences(No.KGCX2-S W-107)~~
文摘This paper focuses on how to reduce the gate leakage current caused by plasma dry etching. X-ray photoelectron spectroscopy （XPS） is employed to measure the AlGaN surface before and after etching. N vacancies are introduced, which cause that gate currents are not dominated by the thermal electron emission mechanism. N vacancies enhance the tunneling effect and reduce the Schottky barrier height as n-type doped in the etched AIGaN surface.A post-gate process for AlGaN/GaN HEMTs,annealing at 400℃ in a nitrogen ambient for 10min is introduced. After annealing, Ni atoms of gate metal reacted with Ga atoms of AlGaN, and N vacancies were reduced. The reverse leakage decreased by three orders of magnitude,the forward turn-on voltage increased and the ideality factor reduced from 3.07 to 2.08.
基金supported by the National Key Scientific Instrument and Equipment Development Projects of China(No.2012YQ17000406)the Foshan-CAS Cooperated Projects(No.2012A01)
文摘Nano-hole patterned sapphire substrates （NHPSSs） were successfully prepared using a low-cost and high-efficiency approach, which is the laser interference lithography （LIL） combined with reactive ion etching （RIE） and inductively coupled plasma （ICP） techniques. Gallium nitride （GaN）-based light emitting diode （LED） structure was grown on NHPSS by metal organic chemical vapor deposition （MOCVD）. Photoluminescence （PL） measurement was conducted to compare the luminescence efficiency of the GaN-based LED structure grown on NHPSS （＇NHPSS-LED） and that on unpatterned sapphire substrates （UPSS-LED）. Electroluminescence （EL） measurement shows that the output power of NHPSS-LED is 2.3 times as high as that of UPSS-LED with an injection current of 150 mA. Both PL and EL results imply that NHPSS has an advantage in improving the crystalline quality of Gab/epilayer and light extraction efficiency of LEDs at the same time.
