Al2O3and HfO2thin films are separately deposited on n-type InAlAs epitaxial layers by using atomic layer deposition(ALD).The interfacial properties are revealed by angle-resolved x-ray photoelectron spectroscopy(AR-XP...Al2O3and HfO2thin films are separately deposited on n-type InAlAs epitaxial layers by using atomic layer deposition(ALD).The interfacial properties are revealed by angle-resolved x-ray photoelectron spectroscopy(AR-XPS).It is demonstrated that the Al2O3layer can reduce interfacial oxidation and trap charge formation.The gate leakage current densities are 1.37×106A/cm2and 3.22×106A/cm2at+1V for the Al2O3/InAlAs and HfO2/InAlAs MOS capacitors respectively.Compared with the HfO2/InAlAs metal-oxide-semiconductor(MOS) capacitor,the Al2O3/InAlAS MOS capacitor exhibits good electrical properties in reducing gate leakage current,narrowing down the hysteresis loop,shrinking stretch-out of the C-V characteristics,and significantly reducing the oxide trapped charge(Qot) value and the interface state density(Dit).展开更多
Substantial defects are produced in Al2O3 by 4 MeV Au ion irradiation with a fluence of 4.4×10^15 cm^-2. Ruther- ford baekscattering spectrometry/channeling and cross-sectional transmission electron microscopy me...Substantial defects are produced in Al2O3 by 4 MeV Au ion irradiation with a fluence of 4.4×10^15 cm^-2. Ruther- ford baekscattering spectrometry/channeling and cross-sectional transmission electron microscopy methods are used to investigate the irradiation damage. The 190keV H ions with a fuence of 1×10^17 cm^-2 are used for implanting pristine and Au ion irradiated Al2O3 to explore the irradiation damage effects on the hydrogen retention in Al2O3. The time-of-flight secondary ion mass spectrometry method is used to obtaJn the single hydrogen depth profile and ions mass spectra （IMS）, in which we find that implanted hydrogens interacted with defects produced by Au ion irradiation. In IMS, we also obtain the hydrogen retention at a certain depth. Comparing the hydrogen retention in different Al2O3 samples, it is concluded that the irradiation damage improves the tritium permeation resistance property of Al2O3 under given conditions. This result means that Al2O3 may strengthen its property of reduc/ng tritium permeation under the harsh irradiation environment in fusion reactors.展开更多
Physical simulation is used to study the movement of nonmetallic particles in Al melt in electro- magnetic field. It is found that the terminal velocity of particles in different Reynolds number range has different fu...Physical simulation is used to study the movement of nonmetallic particles in Al melt in electro- magnetic field. It is found that the terminal velocity of particles in different Reynolds number range has different functions. By confirming drag force coefficient of nonmetallic particles with Reynolds number in the range of 0.2-10 and 10-25 respectively, two functions of terminal ve- locity for spherical nonmetallic particles have been got accordingly, which provide a theoretical basis for separating nonmetallic inclusions from Al melt in electromagnetic field.展开更多
基金supported by the National Basic Research Program of China(Grant No.2010CB327505)the Advanced Research Foundation of China(Grant No.914xxx803-051xxx111)+3 种基金the National Defense Advance Research Project,China(Grant No.513xxxxx306)the National Natural Science Foundation of China(Grant No.51302215)the Scientific Research Program Funded by Shaanxi Provincial Education Department,China(Grant No.14JK1656)the Science and Technology Project of Shaanxi Province,China(Grant No.2016KRM029)
文摘Al2O3and HfO2thin films are separately deposited on n-type InAlAs epitaxial layers by using atomic layer deposition(ALD).The interfacial properties are revealed by angle-resolved x-ray photoelectron spectroscopy(AR-XPS).It is demonstrated that the Al2O3layer can reduce interfacial oxidation and trap charge formation.The gate leakage current densities are 1.37×106A/cm2and 3.22×106A/cm2at+1V for the Al2O3/InAlAs and HfO2/InAlAs MOS capacitors respectively.Compared with the HfO2/InAlAs metal-oxide-semiconductor(MOS) capacitor,the Al2O3/InAlAS MOS capacitor exhibits good electrical properties in reducing gate leakage current,narrowing down the hysteresis loop,shrinking stretch-out of the C-V characteristics,and significantly reducing the oxide trapped charge(Qot) value and the interface state density(Dit).
基金Supported by the National Natural Science Foundation of China under Grant Nos 91426304 and 91226202the National Magnetic Confinement Fusion Energy Research Project under Grant No 2015GB113000
文摘Substantial defects are produced in Al2O3 by 4 MeV Au ion irradiation with a fluence of 4.4×10^15 cm^-2. Ruther- ford baekscattering spectrometry/channeling and cross-sectional transmission electron microscopy methods are used to investigate the irradiation damage. The 190keV H ions with a fuence of 1×10^17 cm^-2 are used for implanting pristine and Au ion irradiated Al2O3 to explore the irradiation damage effects on the hydrogen retention in Al2O3. The time-of-flight secondary ion mass spectrometry method is used to obtaJn the single hydrogen depth profile and ions mass spectra （IMS）, in which we find that implanted hydrogens interacted with defects produced by Au ion irradiation. In IMS, we also obtain the hydrogen retention at a certain depth. Comparing the hydrogen retention in different Al2O3 samples, it is concluded that the irradiation damage improves the tritium permeation resistance property of Al2O3 under given conditions. This result means that Al2O3 may strengthen its property of reduc/ng tritium permeation under the harsh irradiation environment in fusion reactors.
基金supported by the National Natural Science Foundation of China(No.59871029)the China Postdoctoral Science Foundation.
文摘Physical simulation is used to study the movement of nonmetallic particles in Al melt in electro- magnetic field. It is found that the terminal velocity of particles in different Reynolds number range has different functions. By confirming drag force coefficient of nonmetallic particles with Reynolds number in the range of 0.2-10 and 10-25 respectively, two functions of terminal ve- locity for spherical nonmetallic particles have been got accordingly, which provide a theoretical basis for separating nonmetallic inclusions from Al melt in electromagnetic field.
