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Formation of boron nitride and silicon nitride bilayer films by ion beam enhanced deposition
Abstracts
The experimental results show that the size of film grain will become bigger and even form a single crystal under special bombarding conditions. It is also found that some factors of substrate, such as lattice structure, lattice parameters and deposited surface, have a great influence upon its growth. A new mechanism of grain growth and how to control the change of film grain in real implantation have been investigated.
Growth of sputtered selenium films Yuan Xianglong, Fang Zhiyao, Min Szukwei and Yu Dawei,
Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China ; and Qi Lei, Shanghai Research Institute of Chemical Industry, Chinese Ministry of Chemical Industry The growing process of sputtered Se films has been investigated with SEM. At the first stage, small droplets were formed randomly on the substrate, then grew up and connected to be a network during sputtering. Finally a continuous film was formed. The number and size of droplets were analyzed with Weibull's distribution function and it was found the distribution characteristics were the same during the growth stage. It coincided nicely with F-Family's Scaling Theory. The effects of substrate temperature and sputtering voltage were also studied. It showed that low substrate temperature and high sputtering voltage were in favor of the formation of small size droplets.
A new approach to obtain homogeneous transparent ZnS thin film interference filter Mei Yuansheng, Department of Physics, Anhui Normal University, Wuhu 241000, Anhui, China; and Shang Shexuan, San Jinan and Shnen Jiangang, Testing and Analytical Centre, Beijing Normal
University, Beijing 100875, China The transparent homogeneity of the ZnS thin film interference filter (which is equivalent to the uniformity of the thin film thickness distribution) is discussed in this article. A certain degree homogeneity of zinc sulphide thin film interference filter can be obtained by adjusting the distance between source and substrate and adjusting the distance of source from the rotating axis. To get a more uniform distribution, a new approach is presented. In the vapour chamber, vapour molecules form a spatial distribution of vapour cloud. The vapour cloud of different shapes results from the temperature of the source, particle scatter, etc. The material deposition on the substrate is related to this cloud distribution. By means of controlling the shape of this vapour cloud, the thin film can be obtained with better homogeneity. F o r the ZnS, NaA1F, interference filter, under certain vapour conditions, the thin film thickness changes gradually from the centre to the edge of substrate, and this results in a change of transmissive wavelength. The area where transmissive wavelength varies by 1 A_from the central wavelength is about 7 x 10-1 cm 2 on the filter. By means of controlling the shape of the vapour cloud, this area can be enlarged to 2-3 cm 2, or even more. A discussion on vapour cloud distribution is also presented in the text.
MOCVD growth of BSCCO superconducting films on various substrates Wang Hong, Wang Xiaofin, Lu Zhikuan, Yu Shuqin, Shang Shuxia, Wang Zhou and Jiang Minhua, Institute of Crystal
Formation of boron nitride and silicon nitride bilayer films by ion beam enhanced deposition
Materials, Shandong University, Jinan 250100, China Bi-Sr~:~a-~u-O superconducting films on MgO, SrTiO2, and KTaO3 substrates have been prepared by metalorganic chemical vapor deposition (MOCVD) using triphenyl bismuth and fldiketonates of Sr, Ca, and Cu as source materials. MOCVD was carried out in a horizontal quartz reactor having separate inlet tubes for introduction of precursors. Source temperatures of 120, 122, 240 and 208°C were employed for Cu(DPM)2, Bi(C6Hs)3, Sr(DPM)2 and Ca(DPM)2, respectively. The flow rates of N2 carrier gas for each source were 60, 80, 300, and 100 cm 3 m i n - 1, respectively, and that of 02 gas was 650 cm 3 min t. Deposition was carried out at normal pressure with the substrate temperature of 600°C. After the deposition, oxygen in situ treatment was carried out for 30 min at 810°C. The films were characterized by energy dispersive X-ray analysis (EDAX), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The temperature dependence of electrical resistance of BSCCO films was measured by a standard four-probe method. The films have an onset To of 90-105 K with zero resistance at 60-80 K. The effect of substrates on the electrical transport properties of BSCCO films are also discussed.
Feng Yiping, Jiang Binyao, Yang Genqing, Huang Wei, Zheng Zhihong, Liu Xianghuai and Zou Shichang, Ion Beam Laboratory,
Shanghai Institute of Metallurgy, Academia Sinica, Shanghai 200050, China A bilayer thin film of boron nitride and silicon nitride has been synthesized by the ion beam enhanced deposition (IBED) technique. Boron (or silicon) was evaporated by electron beam bombardment on substrates and nitrogen ions (N+:N~ " --- 3:4) with energy of 40 keV simultaneously irradiated at room temperature. The component ratio of the films can be controlled and predicted by the atomic arrival rate ratio of nitrogen to boron (or silicon). The composition profiles were determined by Auger electron spectrometry (AES). A strong interdiffusion of boron and silicon atoms was observed at the boron nitride and silicon nitride interface region, which may be explained in the terms of dynamical ion beam enhanced diffusion. Infrared (ir) measurements showed that the characteristic absorption peaks are located at wavenumbers of 1370 c m - l and 780 c m - 1 for h-BN and at 840 cm i for Si3N4, and both absorption peaks were observed in the boron nitride and silicon nitride bilayer films. 1093
The experimental results show that the size of film grain will become bigger and even form a single crystal under special bombarding conditions. It is also found that some factors of substrate, such as lattice structure, lattice parameters and deposited surface, have a great influence upon its growth. A new mechanism of grain growth and how to control the change of film grain in real implantation have been investigated.
Growth of sputtered selenium films Yuan Xianglong, Fang Zhiyao, Min Szukwei and Yu Dawei,
Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China ; and Qi Lei, Shanghai Research Institute of Chemical Industry, Chinese Ministry of Chemical Industry The growing process of sputtered Se films has been investigated with SEM. At the first stage, small droplets were formed randomly on the substrate, then grew up and connected to be a network during sputtering. Finally a continuous film was formed. The number and size of droplets were analyzed with Weibull's distribution function and it was found the distribution characteristics were the same during the growth stage. It coincided nicely with F-Family's Scaling Theory. The effects of substrate temperature and sputtering voltage were also studied. It showed that low substrate temperature and high sputtering voltage were in favor of the formation of small size droplets.
A new approach to obtain homogeneous transparent ZnS thin film interference filter Mei Yuansheng, Department of Physics, Anhui Normal University, Wuhu 241000, Anhui, China; and Shang Shexuan, San Jinan and Shnen Jiangang, Testing and Analytical Centre, Beijing Normal
University, Beijing 100875, China The transparent homogeneity of the ZnS thin film interference filter (which is equivalent to the uniformity of the thin film thickness distribution) is discussed in this article. A certain degree homogeneity of zinc sulphide thin film interference filter can be obtained by adjusting the distance between source and substrate and adjusting the distance of source from the rotating axis. To get a more uniform distribution, a new approach is presented. In the vapour chamber, vapour molecules form a spatial distribution of vapour cloud. The vapour cloud of different shapes results from the temperature of the source, particle scatter, etc. The material deposition on the substrate is related to this cloud distribution. By means of controlling the shape of this vapour cloud, the thin film can be obtained with better homogeneity. F o r the ZnS, NaA1F, interference filter, under certain vapour conditions, the thin film thickness changes gradually from the centre to the edge of substrate, and this results in a change of transmissive wavelength. The area where transmissive wavelength varies by 1 A_from the central wavelength is about 7 x 10-1 cm 2 on the filter. By means of controlling the shape of the vapour cloud, this area can be enlarged to 2-3 cm 2, or even more. A discussion on vapour cloud distribution is also presented in the text.
MOCVD growth of BSCCO superconducting films on various substrates Wang Hong, Wang Xiaofin, Lu Zhikuan, Yu Shuqin, Shang Shuxia, Wang Zhou and Jiang Minhua, Institute of Crystal
Formation of boron nitride and silicon nitride bilayer films by ion beam enhanced deposition
Materials, Shandong University, Jinan 250100, China Bi-Sr~:~a-~u-O superconducting films on MgO, SrTiO2, and KTaO3 substrates have been prepared by metalorganic chemical vapor deposition (MOCVD) using triphenyl bismuth and fldiketonates of Sr, Ca, and Cu as source materials. MOCVD was carried out in a horizontal quartz reactor having separate inlet tubes for introduction of precursors. Source temperatures of 120, 122, 240 and 208°C were employed for Cu(DPM)2, Bi(C6Hs)3, Sr(DPM)2 and Ca(DPM)2, respectively. The flow rates of N2 carrier gas for each source were 60, 80, 300, and 100 cm 3 m i n - 1, respectively, and that of 02 gas was 650 cm 3 min t. Deposition was carried out at normal pressure with the substrate temperature of 600°C. After the deposition, oxygen in situ treatment was carried out for 30 min at 810°C. The films were characterized by energy dispersive X-ray analysis (EDAX), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The temperature dependence of electrical resistance of BSCCO films was measured by a standard four-probe method. The films have an onset To of 90-105 K with zero resistance at 60-80 K. The effect of substrates on the electrical transport properties of BSCCO films are also discussed.
Feng Yiping, Jiang Binyao, Yang Genqing, Huang Wei, Zheng Zhihong, Liu Xianghuai and Zou Shichang, Ion Beam Laboratory,
Shanghai Institute of Metallurgy, Academia Sinica, Shanghai 200050, China A bilayer thin film of boron nitride and silicon nitride has been synthesized by the ion beam enhanced deposition (IBED) technique. Boron (or silicon) was evaporated by electron beam bombardment on substrates and nitrogen ions (N+:N~ " --- 3:4) with energy of 40 keV simultaneously irradiated at room temperature. The component ratio of the films can be controlled and predicted by the atomic arrival rate ratio of nitrogen to boron (or silicon). The composition profiles were determined by Auger electron spectrometry (AES). A strong interdiffusion of boron and silicon atoms was observed at the boron nitride and silicon nitride interface region, which may be explained in the terms of dynamical ion beam enhanced diffusion. Infrared (ir) measurements showed that the characteristic absorption peaks are located at wavenumbers of 1370 c m - l and 780 c m - 1 for h-BN and at 840 cm i for Si3N4, and both absorption peaks were observed in the boron nitride and silicon nitride bilayer films. 1093