The FeSi2 target alloy was fabricated by conventional powder metallurgy technology, and then, β-FeSi2 thin films was successfully prepared by pulsed laser deposition （PLD）. X-ray diffraction （XRD） and field emiss...The FeSi2 target alloy was fabricated by conventional powder metallurgy technology, and then, β-FeSi2 thin films was successfully prepared by pulsed laser deposition （PLD）. X-ray diffraction （XRD） and field emission scanning electron microscopy （FESEM） were used to characterize the structure, composition, and their changes in the process of β-FeSi2 preparation. In addition, a laser sintering process was also employed to prepare FeSi2 alloy. The analysis of radiation heat transfers in different-sized FeSi2 melt indicates that the cooling rate of the melt depends on the size, i.e., the cooling rate of the micron sized melt is 103 times greater than that of the millimeter-sized melt. The product a-FeSi2 by laser sintering and β-FeSi2 by PLD reveals the different phase transition process in crystallization of millimeter-sized and micron-sized （or submicron-sized） FeSi2 melt. The results of PLD preparation process shows that β-FeSi2 could be prepared through a liquid-phase sintering, followed by a rapid cooling.展开更多
We investigate the thermal stability of HfTaON films prepared by physical vapor deposition using high resolution transmission electronic microscope （HRTEM） and X-ray photoelectron spectroscopy （XPS）. The results i...We investigate the thermal stability of HfTaON films prepared by physical vapor deposition using high resolution transmission electronic microscope （HRTEM） and X-ray photoelectron spectroscopy （XPS）. The results indicate that the magnetron-sputtered HfTaON films on Si substrate are not stable during the post-deposition annealing （PDA）. HfTaON will react with Si and form the interfacial layer at the interface between HfTaON and Si substrate. Hf-N bonds are not stale at high temperature and easily replaced by oxygen, resulting in significant loss of nitrogen from the bulk film. SiO2 buffer layer introduction at the interface of HfraON and Si substrate may effectively suppress their reaction and control the formation of thicker interfacial layer. But SiO2 is a low k gate dielectric and too thicker SiO2 buffer layer will increase the gate dielectric＇s equivalent oxide thickness. SiON prepared by oxidation of N-implanted Si substrate has thinner physical thickness than SiO2 and is helpful to reduce the gate dielectric＇s equivalent oxide thickness.展开更多
基金Supported by the Special Funds for Major State Basic Research Project of China (G90923013)the Natural Science Foundation of Department of Education of Hubei Province (20091002-176)
文摘The FeSi2 target alloy was fabricated by conventional powder metallurgy technology, and then, β-FeSi2 thin films was successfully prepared by pulsed laser deposition （PLD）. X-ray diffraction （XRD） and field emission scanning electron microscopy （FESEM） were used to characterize the structure, composition, and their changes in the process of β-FeSi2 preparation. In addition, a laser sintering process was also employed to prepare FeSi2 alloy. The analysis of radiation heat transfers in different-sized FeSi2 melt indicates that the cooling rate of the melt depends on the size, i.e., the cooling rate of the micron sized melt is 103 times greater than that of the millimeter-sized melt. The product a-FeSi2 by laser sintering and β-FeSi2 by PLD reveals the different phase transition process in crystallization of millimeter-sized and micron-sized （or submicron-sized） FeSi2 melt. The results of PLD preparation process shows that β-FeSi2 could be prepared through a liquid-phase sintering, followed by a rapid cooling.
基金supported by the State Key Development Program for Basic Research of China (No. 2006CB302704) the National Natural Science Foundation of China (No. 60776030)
文摘We investigate the thermal stability of HfTaON films prepared by physical vapor deposition using high resolution transmission electronic microscope （HRTEM） and X-ray photoelectron spectroscopy （XPS）. The results indicate that the magnetron-sputtered HfTaON films on Si substrate are not stable during the post-deposition annealing （PDA）. HfTaON will react with Si and form the interfacial layer at the interface between HfTaON and Si substrate. Hf-N bonds are not stale at high temperature and easily replaced by oxygen, resulting in significant loss of nitrogen from the bulk film. SiO2 buffer layer introduction at the interface of HfraON and Si substrate may effectively suppress their reaction and control the formation of thicker interfacial layer. But SiO2 is a low k gate dielectric and too thicker SiO2 buffer layer will increase the gate dielectric＇s equivalent oxide thickness. SiON prepared by oxidation of N-implanted Si substrate has thinner physical thickness than SiO2 and is helpful to reduce the gate dielectric＇s equivalent oxide thickness.
