GaN epilayer grown on Si(111)substrate by a novel vacuum reaction method rather than metal organic chemical vapor deposition or molecule beam epitaxy is reported.Scanning electron micrograph shows that surface of GaN ...GaN epilayer grown on Si(111)substrate by a novel vacuum reaction method rather than metal organic chemical vapor deposition or molecule beam epitaxy is reported.Scanning electron micrograph shows that surface of GaN film is flat and crack-free.A pronounced GaN(0002)peak appears in the x-ray diffraction pattern.The full width at half-maximum(FWHM)of the double-crystal x-ray rocking curve for(0002)diffraction from the GaN epilayer is 30arcmin.The photoluminescence spectrum shows that the GaN epilayer emits light at the wavelength of 365nm with an FWHM of 8nm(74.6meV).展开更多
High quality Si_(1-x-y)Ge_(x)C_(y) alloy with 2.2%C is grown at a relatively high temperature(760℃)on Si(100)using ultra-high vacuum/chemical vapor deposition(UHV/CVD)system.The samples are investigated with high res...High quality Si_(1-x-y)Ge_(x)C_(y) alloy with 2.2%C is grown at a relatively high temperature(760℃)on Si(100)using ultra-high vacuum/chemical vapor deposition(UHV/CVD)system.The samples are investigated with high resolution cross-sectioned transmission electron microscope and x-ray diffraction.Compared with Si_(1-x)Ge_(x) alloys,Si_(1-x-y)Ge_(x)C_(y) alloys with small amounts of Chave much less strain and larger critical layer thickness.The quality of interface is edso improved.Relatively flat growing profiles of the film are confirmed by secondary ion mass spectroscopy.Fourier transform infrared spectroscopy is also used to testify that the carbon atoms are on the substitutional sites.It is proved that the UHV/CVD system is an efficient method of growing Si_(1-x-y)Ge_(x)C_(y) alloys.展开更多
A SiGe/Si epilayer with a linear-step-graded buffer was grown by ultrahigh vacuum chemical vapor deposition technique at a relatively high growth temperature(780℃)and a relatively high growth rate.Almost linear Ge co...A SiGe/Si epilayer with a linear-step-graded buffer was grown by ultrahigh vacuum chemical vapor deposition technique at a relatively high growth temperature(780℃)and a relatively high growth rate.Almost linear Ge content variation was realized in the buffer layer due to the Ge segregation to the growing surface during epitaxial growth.Double crystal x-ray diffraction and Raman spectroscopy show that the upper layer is fully relaxed.However,the measured results show that the density of dislocation in the composition graded structure is much lower than that in single-step epilayer structures.展开更多
基金Supported by thw Talents Across the Century of Education Ministry of Chinathe National Natural Science Foundation of China under Grant No.69890230.
文摘GaN epilayer grown on Si(111)substrate by a novel vacuum reaction method rather than metal organic chemical vapor deposition or molecule beam epitaxy is reported.Scanning electron micrograph shows that surface of GaN film is flat and crack-free.A pronounced GaN(0002)peak appears in the x-ray diffraction pattern.The full width at half-maximum(FWHM)of the double-crystal x-ray rocking curve for(0002)diffraction from the GaN epilayer is 30arcmin.The photoluminescence spectrum shows that the GaN epilayer emits light at the wavelength of 365nm with an FWHM of 8nm(74.6meV).
基金Supported by the National Natural Science Foundation of China under Grant No.69686002.
文摘High quality Si_(1-x-y)Ge_(x)C_(y) alloy with 2.2%C is grown at a relatively high temperature(760℃)on Si(100)using ultra-high vacuum/chemical vapor deposition(UHV/CVD)system.The samples are investigated with high resolution cross-sectioned transmission electron microscope and x-ray diffraction.Compared with Si_(1-x)Ge_(x) alloys,Si_(1-x-y)Ge_(x)C_(y) alloys with small amounts of Chave much less strain and larger critical layer thickness.The quality of interface is edso improved.Relatively flat growing profiles of the film are confirmed by secondary ion mass spectroscopy.Fourier transform infrared spectroscopy is also used to testify that the carbon atoms are on the substitutional sites.It is proved that the UHV/CVD system is an efficient method of growing Si_(1-x-y)Ge_(x)C_(y) alloys.
基金Supported by the National Natural Science Foundation of China under Grant No.69686002the‘Talents Across the Century’of Education Ministry of Chinathe Natural Science Fund of Zhejiang Province.
文摘A SiGe/Si epilayer with a linear-step-graded buffer was grown by ultrahigh vacuum chemical vapor deposition technique at a relatively high growth temperature(780℃)and a relatively high growth rate.Almost linear Ge content variation was realized in the buffer layer due to the Ge segregation to the growing surface during epitaxial growth.Double crystal x-ray diffraction and Raman spectroscopy show that the upper layer is fully relaxed.However,the measured results show that the density of dislocation in the composition graded structure is much lower than that in single-step epilayer structures.
