Au films with a thickness of about 300 nm were deposited on SiO_2/Si(100) andmica substrates by dc sputtering. X-ray diffraction spectroscopy and field emission scanningelectron microscopy were used to analyze the str...Au films with a thickness of about 300 nm were deposited on SiO_2/Si(100) andmica substrates by dc sputtering. X-ray diffraction spectroscopy and field emission scanningelectron microscopy were used to analyze the structure and internal stress of the Au films. Thefirms grown on SiO_2/Si(100) show a preferential orientation of [111] in the growth direction.However the films grown on mica have mixture crystalline orientations of [111], [200], [220] and[311] in the growth direction and the orientations of [200] and [311] are slightly more than thoseof [111] and [220]. An internal stress in the films grown on SiO_2/Si(100) is tensile. For Au filmsgrown on mica the internal stresses in the [111]- and [311]-orientation grains are compressive whilethose in the [200]- and [220]-orientation grains are tensile. Au films grown SiO_2/Si(100) havesome very large grains with a size of about 400 nm and have a wider grain size distribution comparedwith those grown on mica.展开更多
An Sr/Si（100）-c（2 ×4） surface is investigated by high-resolution scanning tunneling microscopy （STM） and scanning tunneling spectroscopy （STS）. The semiconductor property of this surface is confirmed by S...An Sr/Si（100）-c（2 ×4） surface is investigated by high-resolution scanning tunneling microscopy （STM） and scanning tunneling spectroscopy （STS）. The semiconductor property of this surface is confirmed by STS. The STM images of this surface shows that it is bias-voltage dependent and an atomic resolution image can be obtained at an empty state under a bias voltage of 1.5 V. Furthermore, one-dimensional （ID） diffusion of vacancies can be found in the room-temperature STM images. Sr vacancies diffuse along the valley channels, which are constructed by silicon dimers in the surface. Weak interaction between Sr and silicon dimers, low metal coverage, surface vacancy, and energy of thermal fluctuation at room temperature all contribute to this 1D diffusion.展开更多
Porous SiO_(2)film has been widely studied due to its extensive applications in many fields.This paper presents a newly produced porous SiO_(2)film made by traditional sol-gel method.Bare Si and Si with SiO_(2)buffer ...Porous SiO_(2)film has been widely studied due to its extensive applications in many fields.This paper presents a newly produced porous SiO_(2)film made by traditional sol-gel method.Bare Si and Si with SiO_(2)buffer layer were used as substrate.The SiO_(2)buffer layer was 500 nm in thickness and was grown by thermal oxidization.The structural properties of SiO_(2)aerogel films spincoated on both materials were observed by optical microscope(OM)and scanning electron microscope(SEM).Results reveal that the surface of SiO_(2)aerogel films on bare Si is rough and discontinuous.While flat and smooth surface is observed on sample with SiO_(2)buffer layer.This indicates that by inserting SiO_(2)buffer layer,the structural property of SiO_(2)aerogel film deposited on Si is improved.展开更多
Long-lasting constant loading commonly exists in silicon-based microelectronic contact and can lead to the appearance of plastic deformation.Stress relaxation behaviors of monocrystalline silicon coated with amorphous...Long-lasting constant loading commonly exists in silicon-based microelectronic contact and can lead to the appearance of plastic deformation.Stress relaxation behaviors of monocrystalline silicon coated with amorphous SiO_(2)film during nanoindentation are probed using molecular dynamics simulation by varying the indenter’s size.The results show that the indentation force(stress)declines sharply at the initial and decreases almost linearly toward the end of holding for tested samples.The amount of stress relaxation of SiO_(2)/Si samples indented with different indenters during holding increases with growing indenter size,and the corresponding plastic deformation characteristics are carefully analyzed.The deformation mechanism for confined amorphous SiO_(2)film is depicted based on the amorphous plasticity theories,revealing that the more activated shear transformation zones(STZs)and free volume within indented SiO_(2)film promote stress relaxation.The phase transformation takes place to monocrystalline silicon,the generated atoms of Si-II and bct-5 phases within monocrystalline silicon substrate during holding are much higher than those for smaller indenter.展开更多
High pressure has a significant influence onβ-FeSi_2 band gaps and optical absorption tuning.In this work,using density functional theory,we investigate the effect of high pressure on the optical absorption behavior ...High pressure has a significant influence onβ-FeSi_2 band gaps and optical absorption tuning.In this work,using density functional theory,we investigate the effect of high pressure on the optical absorption behavior of aβ-FeSi_2（100）/Si（001） interface with some Si vacancies.As the pressure increases,the optical absorption peak down-shifts firstly,reach minimum values,and then un-shifts slowly.The electronic orbital analysis indicates that the electronic transition between the highest occupied states and the lowest unoccupied states mainly originate from Fe atoms at the interface regions.Structural analysis discloses that the Si（001） slab partially offsets the pressure exerted on theβ-FeSi_2（100） interface,but this effect will become weaker with further increasing pressure,and this physical mechanism plays an important role in its optical absorption behavior.展开更多
文摘Au films with a thickness of about 300 nm were deposited on SiO_2/Si(100) andmica substrates by dc sputtering. X-ray diffraction spectroscopy and field emission scanningelectron microscopy were used to analyze the structure and internal stress of the Au films. Thefirms grown on SiO_2/Si(100) show a preferential orientation of [111] in the growth direction.However the films grown on mica have mixture crystalline orientations of [111], [200], [220] and[311] in the growth direction and the orientations of [200] and [311] are slightly more than thoseof [111] and [220]. An internal stress in the films grown on SiO_2/Si(100) is tensile. For Au filmsgrown on mica the internal stresses in the [111]- and [311]-orientation grains are compressive whilethose in the [200]- and [220]-orientation grains are tensile. Au films grown SiO_2/Si(100) havesome very large grains with a size of about 400 nm and have a wider grain size distribution comparedwith those grown on mica.
基金supported by the National Natural Science Foundation of China (Grant No. 60771066)
文摘An Sr/Si（100）-c（2 ×4） surface is investigated by high-resolution scanning tunneling microscopy （STM） and scanning tunneling spectroscopy （STS）. The semiconductor property of this surface is confirmed by STS. The STM images of this surface shows that it is bias-voltage dependent and an atomic resolution image can be obtained at an empty state under a bias voltage of 1.5 V. Furthermore, one-dimensional （ID） diffusion of vacancies can be found in the room-temperature STM images. Sr vacancies diffuse along the valley channels, which are constructed by silicon dimers in the surface. Weak interaction between Sr and silicon dimers, low metal coverage, surface vacancy, and energy of thermal fluctuation at room temperature all contribute to this 1D diffusion.
基金financially supported by the National Natural Science Foundation of China(No.51102037)the Fundamental Research Funds for the Central Universities from UESTC(Nos.ZYGX2010J030 and ZYGX2011J023)。
文摘Porous SiO_(2)film has been widely studied due to its extensive applications in many fields.This paper presents a newly produced porous SiO_(2)film made by traditional sol-gel method.Bare Si and Si with SiO_(2)buffer layer were used as substrate.The SiO_(2)buffer layer was 500 nm in thickness and was grown by thermal oxidization.The structural properties of SiO_(2)aerogel films spincoated on both materials were observed by optical microscope(OM)and scanning electron microscope(SEM).Results reveal that the surface of SiO_(2)aerogel films on bare Si is rough and discontinuous.While flat and smooth surface is observed on sample with SiO_(2)buffer layer.This indicates that by inserting SiO_(2)buffer layer,the structural property of SiO_(2)aerogel film deposited on Si is improved.
基金the National Natural Science Foundation of China(Nos.51375364,51575372)Doctor Funds of Taiyuan University of Science and Technology(No.20202004)。
文摘Long-lasting constant loading commonly exists in silicon-based microelectronic contact and can lead to the appearance of plastic deformation.Stress relaxation behaviors of monocrystalline silicon coated with amorphous SiO_(2)film during nanoindentation are probed using molecular dynamics simulation by varying the indenter’s size.The results show that the indentation force(stress)declines sharply at the initial and decreases almost linearly toward the end of holding for tested samples.The amount of stress relaxation of SiO_(2)/Si samples indented with different indenters during holding increases with growing indenter size,and the corresponding plastic deformation characteristics are carefully analyzed.The deformation mechanism for confined amorphous SiO_(2)film is depicted based on the amorphous plasticity theories,revealing that the more activated shear transformation zones(STZs)and free volume within indented SiO_(2)film promote stress relaxation.The phase transformation takes place to monocrystalline silicon,the generated atoms of Si-II and bct-5 phases within monocrystalline silicon substrate during holding are much higher than those for smaller indenter.
基金Project supported by the National Natural Science Foundation of China(No.61264008)
文摘High pressure has a significant influence onβ-FeSi_2 band gaps and optical absorption tuning.In this work,using density functional theory,we investigate the effect of high pressure on the optical absorption behavior of aβ-FeSi_2（100）/Si（001） interface with some Si vacancies.As the pressure increases,the optical absorption peak down-shifts firstly,reach minimum values,and then un-shifts slowly.The electronic orbital analysis indicates that the electronic transition between the highest occupied states and the lowest unoccupied states mainly originate from Fe atoms at the interface regions.Structural analysis discloses that the Si（001） slab partially offsets the pressure exerted on theβ-FeSi_2（100） interface,but this effect will become weaker with further increasing pressure,and this physical mechanism plays an important role in its optical absorption behavior.
