A new technique for the preparation of AlN thin films by ultrahigh vacuum electron beam evaporation of AI followed by nitridation is reported and by using this method c-axis oriented AJN thin films have been success-f...A new technique for the preparation of AlN thin films by ultrahigh vacuum electron beam evaporation of AI followed by nitridation is reported and by using this method c-axis oriented AJN thin films have been success-fully grown on Si(111)substrates.X-ray diffraction,Fourier transform infrared spectroscopy,x-ray photoelectron spectroscopy and cross-sectional transmission electron microscope were employed to characterize AIN films.Temperature of nitridation was found to play an important role in the formation of AIN film.By post-nitridation of as-deposited film at 1000℃ for lh in N2,the crystalline AlN film with(002)orientation has been obtained.展开更多
The 4×10^(16)/cm^(2) H+and 9×10^(16)/cm^(2) He+have been implanted into the silicon substrate of separation-by-implantation-of oxygen(SIMOX)wafers,respectively,followed by a 700℃ annealing to form nanocavit...The 4×10^(16)/cm^(2) H+and 9×10^(16)/cm^(2) He+have been implanted into the silicon substrate of separation-by-implantation-of oxygen(SIMOX)wafers,respectively,followed by a 700℃ annealing to form nanocavities beneath the buried oxide(BOX)layer.The SIMOX wafers were intentionally contaminated with Cu impurities by implanting different doses of Cu in the top Si layer.Secondary ion mass spectroscopy and cross-sectional transmission electron microscopy technologies have been employed to investigate the gettering effect of nanocavities to the Cu impurities.The cavities induced either by H^(+) or He^(+) implantation are effective gettering centers for Cu in SIMOX wafers.After annealing at 1000℃ for 90 min,up to 4×10^(15)/cm^(2) Cu has diffused through the BOX layer and been captured by the cavities.The gettering efficiency of cavities increases with the decrease of Cu implantation doses.The nanocavities provide an attractive method for gettering transition metal impurities in SIMOX materials.展开更多
C-axis oriented Y1Ba_(2)Cu_(3)O_(7-x)(YBCO)thin films and PbZr_(0.52)Ti_(0.48)O_(3)(PZT)/(YBCO)heterostructures were deposited on single-crystal LaAIO3 by Nd:YAG pulsed laser deposition.The results showed that the YBC...C-axis oriented Y1Ba_(2)Cu_(3)O_(7-x)(YBCO)thin films and PbZr_(0.52)Ti_(0.48)O_(3)(PZT)/(YBCO)heterostructures were deposited on single-crystal LaAIO3 by Nd:YAG pulsed laser deposition.The results showed that the YBCO films exhibited superconducting transition temperature above 86 K and ion beam channeling minimum yields xmin of 49%,indicating the relatively good quality of YBCO films deposited on the LaAIO3 substrate.The PZT films in situ grown on the YBCO films were epitaxially c-axis oriented with a saturation polarization and remanence as high as 57μC/cm_(2) and 39μC/cm^(2)(at 204 kV/cm),respectively.The coercive field of PZT films is about 55 kV/cm.展开更多
基金Supported by the Shanghai Youth Foundation under Grant No.97QD14034the National Natural Science Foundation of China under Grant No.69776003.
文摘A new technique for the preparation of AlN thin films by ultrahigh vacuum electron beam evaporation of AI followed by nitridation is reported and by using this method c-axis oriented AJN thin films have been success-fully grown on Si(111)substrates.X-ray diffraction,Fourier transform infrared spectroscopy,x-ray photoelectron spectroscopy and cross-sectional transmission electron microscope were employed to characterize AIN films.Temperature of nitridation was found to play an important role in the formation of AIN film.By post-nitridation of as-deposited film at 1000℃ for lh in N2,the crystalline AlN film with(002)orientation has been obtained.
文摘The 4×10^(16)/cm^(2) H+and 9×10^(16)/cm^(2) He+have been implanted into the silicon substrate of separation-by-implantation-of oxygen(SIMOX)wafers,respectively,followed by a 700℃ annealing to form nanocavities beneath the buried oxide(BOX)layer.The SIMOX wafers were intentionally contaminated with Cu impurities by implanting different doses of Cu in the top Si layer.Secondary ion mass spectroscopy and cross-sectional transmission electron microscopy technologies have been employed to investigate the gettering effect of nanocavities to the Cu impurities.The cavities induced either by H^(+) or He^(+) implantation are effective gettering centers for Cu in SIMOX wafers.After annealing at 1000℃ for 90 min,up to 4×10^(15)/cm^(2) Cu has diffused through the BOX layer and been captured by the cavities.The gettering efficiency of cavities increases with the decrease of Cu implantation doses.The nanocavities provide an attractive method for gettering transition metal impurities in SIMOX materials.
基金Supported by the National Advanced Materials Committee of China under Grant No.715-002-0110.
文摘C-axis oriented Y1Ba_(2)Cu_(3)O_(7-x)(YBCO)thin films and PbZr_(0.52)Ti_(0.48)O_(3)(PZT)/(YBCO)heterostructures were deposited on single-crystal LaAIO3 by Nd:YAG pulsed laser deposition.The results showed that the YBCO films exhibited superconducting transition temperature above 86 K and ion beam channeling minimum yields xmin of 49%,indicating the relatively good quality of YBCO films deposited on the LaAIO3 substrate.The PZT films in situ grown on the YBCO films were epitaxially c-axis oriented with a saturation polarization and remanence as high as 57μC/cm_(2) and 39μC/cm^(2)(at 204 kV/cm),respectively.The coercive field of PZT films is about 55 kV/cm.
