At room temperature, 300 K, silicon carbide film was formed using monomethylsilane gas on the reactive surface prepared using argon plasma. Entire process was performed at reduced pressure of 10 Pa in the argon plasma...At room temperature, 300 K, silicon carbide film was formed using monomethylsilane gas on the reactive surface prepared using argon plasma. Entire process was performed at reduced pressure of 10 Pa in the argon plasma etcher, without a substrate transfer operation. By this process, the several-nanometer-thick amorphous thin film containing silicon-carbon bonds was obtained on various substrates, such as semiconductor silicon, aluminum and stainless steel. It is concluded that the room temperature silicon carbide thin film formation is possible even at significantly low pressure, when the substrate surface is reactive.展开更多
Monte Carlo simulations are adopted to study the electron motion in the mixture of H2 and CH4 during diamond synthesis via Glow Plasma-assisted Chemical Vapor Deposition (GPCVD). The non-uniform electric field is used...Monte Carlo simulations are adopted to study the electron motion in the mixture of H2 and CH4 during diamond synthesis via Glow Plasma-assisted Chemical Vapor Deposition (GPCVD). The non-uniform electric field is used and the avalanche of electrons is taken into account in this simulation. The average energy distribution of electrons and the space distribution of effective species such as CH3, CH+3, CH+ and H at various gas pressures are given in this paper, and optimum experimental conditions are inferred from these results.展开更多
A mass of nanoparticles/nanorods were formed on a simultaneously deposited gran- ular film by plasma enhanced chemical vapor deposition (PECVD) of perfluorohexane at atmo- spheric pressure without any catalysts or t...A mass of nanoparticles/nanorods were formed on a simultaneously deposited gran- ular film by plasma enhanced chemical vapor deposition (PECVD) of perfluorohexane at atmo- spheric pressure without any catalysts or templates. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to characterize the morphology and the chem- ical compositions of nanoparticles. The average size of particles is about 100 nm and the length of synthesized nanorods is between 1 μm and 2.5/tm. The analyses of transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction(SAED) and X-ray diffraction (XRD) reveals that the nanoparticles and nanorods are crystalline.展开更多
Atomically thin MoS2 films have attracted significant attention due to excellent electrical and optical properties.The development of device applications demands the production of large-area thin film which is still a...Atomically thin MoS2 films have attracted significant attention due to excellent electrical and optical properties.The development of device applications demands the production of large-area thin film which is still an obstacle.In this work we developed a facile method to directly grow large-area MoS2 thin film on Si O2 substrate via ambient pressure chemical vapor deposition method. The characterizations by spectroscopy and electron microscopy reveal that the as-grown MoS2 film is mainly bilayer and trilayer with high quality. Back-gate field-effect transistor based on such MoS2 thin film shows carrier mobility up to 3.4 cm2V-1s-1 and on/off ratio of 105. The large-area atomically thin MoS2 prepared in this work has the potential for wide optoelectronic and photonic device applications.展开更多
3C-SiC heteroepitaxial layers were grown on Si substrates using a horizontal,hot-wall low pressure chemical vapor deposition system.The crystal quality,surface morphology and thickness uniformity of the layers were ch...3C-SiC heteroepitaxial layers were grown on Si substrates using a horizontal,hot-wall low pressure chemical vapor deposition system.The crystal quality,surface morphology and thickness uniformity of the layers were characterized by X-ray diffraction,atomic force microcopy and Fourier transform infrared spectroscopy,respectively.Growth of the epitaxial layer was determined to follow a three-dimensional island mode initially and then switch to a step-flow mode as the growth time increases.展开更多
Atmospheric pressure plasma jet(APPJ)was used to clean nitrogen-containing carbon films(C–N)fabricated by plasma-assisted chemical vapor deposition method employing the plasma surface interaction linear device at Sic...Atmospheric pressure plasma jet(APPJ)was used to clean nitrogen-containing carbon films(C–N)fabricated by plasma-assisted chemical vapor deposition method employing the plasma surface interaction linear device at Sichuan University(SCU-PSI).The properties of the contaminated films on the surface of pristine and He-plasma pre-irradiated tungsten matrix,such as morphology,crystalline structure,element composition and chemical structure were characterized by scanning electron microscopy,grazing incidence x-ray diffraction and x-ray photoelectron spectroscopy.The experimental results revealed that the removal of C–N film with a thickness of tens of microns can be realized through APPJ cleaning regardless of the morphology of the substrates.Similar removal rates of 16.82 and 13.78μm min^(-1)were obtained for C–N films deposited on a smooth pristine W surface and rough fuzz-covered W surface,respectively.This is a remarkable improvement in comparison to the traditional cleaning method.However,slight surface oxidation was found after APPJ cleaning,but the degree of oxidation was acceptable with an oxidation depth increase of only 3.15 nm.Optical emission spectroscopy analysis and mass spectrometry analysis showed that C–N contamination was mainly removed through chemical reaction with reactive oxygen species during APPJ treatment using air as the working gas.These results make APPJ cleaning a potentially effective method for the rapid removal of C–N films from the wall surfaces of fusion devices.展开更多
In this paper, we investigate the effect of pressure on the growth mode of high quality (10-11) GaN using an epi- taxial lateral over growth (ELO) technique by metal organic chemical vapor deposition (MOCVD). Tw...In this paper, we investigate the effect of pressure on the growth mode of high quality (10-11) GaN using an epi- taxial lateral over growth (ELO) technique by metal organic chemical vapor deposition (MOCVD). Two pressure growth conditions, high pressure (HP) 1013 mbar and low pressure growth (LP) 500 mbar, are employed during growth. In the high pressure growth conditions, the crystal quality is improved by decreasing the dislocation and stack fault density in the strip connection locations. The room temperature photoluminescence measurement also shows that the light emission intensity increases three times using the HP growth condition compared with that using the LP growth conditions. In the low temperature (77 K) photoluminescence, the defects-related peaks are very obvious in the low pressure growth samples. This result also indicates that the crystal quality is improved using the high pressure growth conditions.展开更多
Arc in vacuum is one of the important methods used to prepare carbon materials. However, the use of vacuum increases the cost of the arc method. This paper introduces an arc discharge device working at atmospheric pre...Arc in vacuum is one of the important methods used to prepare carbon materials. However, the use of vacuum increases the cost of the arc method. This paper introduces an arc discharge device working at atmospheric pressure. The current-limiting resistor, capacitor and inductor make the discharge gentle. The electrode temperature can be adjusted from 2040 K to 3673 K. Carbon nanofibres were prepared at the electrode temperature of 3645 K by using this device.展开更多
TiO_(2) thin films were prepared on Pt/Ti/SiO_(2)/Si substrate by laser chemical vapor deposition(LCVD)method.The effects of laser power(P_(L))and total pressure(p_(tot))on the microstructure of TiO_(2) thin films wer...TiO_(2) thin films were prepared on Pt/Ti/SiO_(2)/Si substrate by laser chemical vapor deposition(LCVD)method.The effects of laser power(P_(L))and total pressure(p_(tot))on the microstructure of TiO_(2) thin films were investigated.The deposition temperature(T_(dep))was mainly affected by P_(L),increasing with P_(L) increasing.The single-phase rutile TiO_(2) thin films with different morphologies were obtained.The morphologies of TiO_(2) thin films were classified into three typical types,including the powdery,Wulff-shaped and granular microstructures.p_(tot) and T_(dep) were the two critical factors that could be effectively used for controlling the morphology of the films.展开更多
低压化学气相沉积法(Low-Pressure Chemical Vapor Deposition,LPCVD)沉积的氮化硅薄膜(LPSi_(3)N_(4))具有质量高、副产物少、厚度均匀性好等特性,常应用于局部氧化的掩蔽膜、电容的介质膜、层间绝缘膜等工艺制程。介绍低压化学气相沉...低压化学气相沉积法(Low-Pressure Chemical Vapor Deposition,LPCVD)沉积的氮化硅薄膜(LPSi_(3)N_(4))具有质量高、副产物少、厚度均匀性好等特性,常应用于局部氧化的掩蔽膜、电容的介质膜、层间绝缘膜等工艺制程。介绍低压化学气相沉积氮化硅薄膜(LPSi_(3)N_(4))的制备工艺,以及不同工艺参数的调试对氮化硅薄膜均匀性和沉积速率的影响。展开更多
文摘At room temperature, 300 K, silicon carbide film was formed using monomethylsilane gas on the reactive surface prepared using argon plasma. Entire process was performed at reduced pressure of 10 Pa in the argon plasma etcher, without a substrate transfer operation. By this process, the several-nanometer-thick amorphous thin film containing silicon-carbon bonds was obtained on various substrates, such as semiconductor silicon, aluminum and stainless steel. It is concluded that the room temperature silicon carbide thin film formation is possible even at significantly low pressure, when the substrate surface is reactive.
基金This work was supported by Doctor Foundation of Hebei Education Committee Hebei Natural Science Foundation(599091 ) of China
文摘Monte Carlo simulations are adopted to study the electron motion in the mixture of H2 and CH4 during diamond synthesis via Glow Plasma-assisted Chemical Vapor Deposition (GPCVD). The non-uniform electric field is used and the avalanche of electrons is taken into account in this simulation. The average energy distribution of electrons and the space distribution of effective species such as CH3, CH+3, CH+ and H at various gas pressures are given in this paper, and optimum experimental conditions are inferred from these results.
基金National Natural Science Foundation of China(No.50473003)
文摘A mass of nanoparticles/nanorods were formed on a simultaneously deposited gran- ular film by plasma enhanced chemical vapor deposition (PECVD) of perfluorohexane at atmo- spheric pressure without any catalysts or templates. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to characterize the morphology and the chem- ical compositions of nanoparticles. The average size of particles is about 100 nm and the length of synthesized nanorods is between 1 μm and 2.5/tm. The analyses of transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction(SAED) and X-ray diffraction (XRD) reveals that the nanoparticles and nanorods are crystalline.
基金the National High Technology Research and Development Program of China (863 Program) (Grant No.2013AA031903)the Youth 973 Program (Grant No.2015CB932700)+7 种基金the National Natural Science Foundation of China (Grant Nos.91433107, 51222208, and 51290273)the Doctoral Fund of Ministry of Education of China (Grant No.20123201120026)ARC DP (DP140101501)ARC DECRA (DE120101569)Victoria DSI top-up grantthe Natural Science Foundation of Jiangsu Province (No.BK20130328)China Postdoctoral Science Foundation (No. 2014M551654)Jiangsu Province Postdoctoral Science Foundation (No.1301020A)
文摘Atomically thin MoS2 films have attracted significant attention due to excellent electrical and optical properties.The development of device applications demands the production of large-area thin film which is still an obstacle.In this work we developed a facile method to directly grow large-area MoS2 thin film on Si O2 substrate via ambient pressure chemical vapor deposition method. The characterizations by spectroscopy and electron microscopy reveal that the as-grown MoS2 film is mainly bilayer and trilayer with high quality. Back-gate field-effect transistor based on such MoS2 thin film shows carrier mobility up to 3.4 cm2V-1s-1 and on/off ratio of 105. The large-area atomically thin MoS2 prepared in this work has the potential for wide optoelectronic and photonic device applications.
基金supported by the National Natural Science Foundation of China(60876061)the Pre-research Project(51308040302)
文摘3C-SiC heteroepitaxial layers were grown on Si substrates using a horizontal,hot-wall low pressure chemical vapor deposition system.The crystal quality,surface morphology and thickness uniformity of the layers were characterized by X-ray diffraction,atomic force microcopy and Fourier transform infrared spectroscopy,respectively.Growth of the epitaxial layer was determined to follow a three-dimensional island mode initially and then switch to a step-flow mode as the growth time increases.
基金funded by National Key Research, Development Program of China (No. 2017YFE0301305KYWX-002)Sichuan Science and Technology Program (No. 2021YFSY0015)
文摘Atmospheric pressure plasma jet(APPJ)was used to clean nitrogen-containing carbon films(C–N)fabricated by plasma-assisted chemical vapor deposition method employing the plasma surface interaction linear device at Sichuan University(SCU-PSI).The properties of the contaminated films on the surface of pristine and He-plasma pre-irradiated tungsten matrix,such as morphology,crystalline structure,element composition and chemical structure were characterized by scanning electron microscopy,grazing incidence x-ray diffraction and x-ray photoelectron spectroscopy.The experimental results revealed that the removal of C–N film with a thickness of tens of microns can be realized through APPJ cleaning regardless of the morphology of the substrates.Similar removal rates of 16.82 and 13.78μm min^(-1)were obtained for C–N films deposited on a smooth pristine W surface and rough fuzz-covered W surface,respectively.This is a remarkable improvement in comparison to the traditional cleaning method.However,slight surface oxidation was found after APPJ cleaning,but the degree of oxidation was acceptable with an oxidation depth increase of only 3.15 nm.Optical emission spectroscopy analysis and mass spectrometry analysis showed that C–N contamination was mainly removed through chemical reaction with reactive oxygen species during APPJ treatment using air as the working gas.These results make APPJ cleaning a potentially effective method for the rapid removal of C–N films from the wall surfaces of fusion devices.
基金support by the National High Technology Research and Development Program of China(Green Laser)
文摘In this paper, we investigate the effect of pressure on the growth mode of high quality (10-11) GaN using an epi- taxial lateral over growth (ELO) technique by metal organic chemical vapor deposition (MOCVD). Two pressure growth conditions, high pressure (HP) 1013 mbar and low pressure growth (LP) 500 mbar, are employed during growth. In the high pressure growth conditions, the crystal quality is improved by decreasing the dislocation and stack fault density in the strip connection locations. The room temperature photoluminescence measurement also shows that the light emission intensity increases three times using the HP growth condition compared with that using the LP growth conditions. In the low temperature (77 K) photoluminescence, the defects-related peaks are very obvious in the low pressure growth samples. This result also indicates that the crystal quality is improved using the high pressure growth conditions.
文摘Arc in vacuum is one of the important methods used to prepare carbon materials. However, the use of vacuum increases the cost of the arc method. This paper introduces an arc discharge device working at atmospheric pressure. The current-limiting resistor, capacitor and inductor make the discharge gentle. The electrode temperature can be adjusted from 2040 K to 3673 K. Carbon nanofibres were prepared at the electrode temperature of 3645 K by using this device.
基金This work was supported in part by the Global COE Program of the Materials Integration,Tohoku University,and the International Science and Technology Cooperation Program of China(Grant No.2009DFB50470)This work was also supported in part by the International Science and Technology Cooperation Project of Hubei Province(Grant No.2010BFA017)and the 111 Project of China(Grant No.B13035).
文摘TiO_(2) thin films were prepared on Pt/Ti/SiO_(2)/Si substrate by laser chemical vapor deposition(LCVD)method.The effects of laser power(P_(L))and total pressure(p_(tot))on the microstructure of TiO_(2) thin films were investigated.The deposition temperature(T_(dep))was mainly affected by P_(L),increasing with P_(L) increasing.The single-phase rutile TiO_(2) thin films with different morphologies were obtained.The morphologies of TiO_(2) thin films were classified into three typical types,including the powdery,Wulff-shaped and granular microstructures.p_(tot) and T_(dep) were the two critical factors that could be effectively used for controlling the morphology of the films.
文摘低压化学气相沉积法(Low-Pressure Chemical Vapor Deposition,LPCVD)沉积的氮化硅薄膜(LPSi_(3)N_(4))具有质量高、副产物少、厚度均匀性好等特性,常应用于局部氧化的掩蔽膜、电容的介质膜、层间绝缘膜等工艺制程。介绍低压化学气相沉积氮化硅薄膜(LPSi_(3)N_(4))的制备工艺,以及不同工艺参数的调试对氮化硅薄膜均匀性和沉积速率的影响。