A novel plasma source suitable for controllable nanostructured thin film deposition processes is proposed. It exploits the separation of the process in two distinct phases. First precursor dissociation and radical for...A novel plasma source suitable for controllable nanostructured thin film deposition processes is proposed. It exploits the separation of the process in two distinct phases. First precursor dissociation and radical formation is performed in a dense oxidizing plasma. Then nucleation and aggregation of molecular clusters occur during the expansion into vacuum of a supersonic jet. This allows a superior control of cluster size and energy in the process of film growth. Characterization of the plasma state and source performances in precursor dissociation have been investigated. The performances of this new Plasma Assisted Supersonic Jet Deposition technique were demonstrated using organic compounds of titanium to obtain TiO2 thin nanostructured films.展开更多
The emission spectra of microwave plasma was in line measured in visible light wave band using a self made optical fiber spectrometer, the change rule of the atomic hydrogen ( H ) and double carbon radical( C 2) was g...The emission spectra of microwave plasma was in line measured in visible light wave band using a self made optical fiber spectrometer, the change rule of the atomic hydrogen ( H ) and double carbon radical( C 2) was given under different CH 4/H 2 ratios of volume flow. The effect of atomic hydrogen ( H ) on CVD diamond, deposited high quality and transparent diamond film by microwave plasma CVD (MPCVD) was analyzed according to the measured results by scanning electron microscopy(SEM), laser Raman spectrometry(Raman), and Fourier transform infrared spectrometry(FTIR). The results showed that the diamond film consisted of (220) orientation and it was homogeneous, compact, low defective, high quality film, its infrared transmissibility was about 70%, approached theoretical transmissibility of diamond. It was key conditions that a large number of atomic hydrogen ( H γ ) and double carbon radical( C 2) exist in the course of high quality diamond film growth. The research provided a rapid method for technology exploration of microwawe plasma CVD, and a reliable basis for research on growth mechanism of diamond film.展开更多
In this study,uniform diamond films with a diameter of 100 mm were deposited in a 15 kW/2.45 GHz ellipsoidal microwave plasma chemical vapour deposition system.A phenomenological model previously developed by our grou...In this study,uniform diamond films with a diameter of 100 mm were deposited in a 15 kW/2.45 GHz ellipsoidal microwave plasma chemical vapour deposition system.A phenomenological model previously developed by our group was used to simulate the distribution of the electric strength and electron density of plasma.Results indicate that the electric field in the cavity includes multiple modes,i.e.TM_(02) and TM_(03).When the gas pressure exceeds 10 kPa,the electron density of plasma increases and plasma volume decreases.A T-shaped substrate was developed to achieve uniform temperature,and the substrate was suspended in air fromφ70 to 100 mm,thus eliminating vertical heat dissipation.An edge electric field was added to the system after the introduction of the T-shaped substrate.Moreover,the plasma volume in this case was greater than that in the central electric field but smaller than that in the periphery electric field of the TM_(02) mode.This indicates that the electric field above and below the edge benefits the plasma volume rather than the periphery electric field of the TM_(02) mode.The quality,uniformity and surface morphology of the deposited diamond films were primarily investigated to maintain substrate temperature uniformity.When employing the improved substrate,the thickness unevenness of theφ100 mm diamond film decreased from 22%to 7%.展开更多
This work proposed to change the structure of the sample susceptor of the microwave plasma chemical vapor deposition(MPCVD)reaction chamber,that is,to introduce a small hole in the center of the susceptor to study its...This work proposed to change the structure of the sample susceptor of the microwave plasma chemical vapor deposition(MPCVD)reaction chamber,that is,to introduce a small hole in the center of the susceptor to study its suppression effect on the incorporation of residual nitrogen in the MPCVD diamond film.By using COMSOL multiphysics software simulation,the plasma characteristics and the concentration of chemical reactants in the cylindrical cavity of MPCVD system were studied,including electric field intensity,electron number density,electron temperature,the concentrations of atomic hydrogen,methyl,and nitrogenous substances,etc.After introducing a small hole in the center of the molybdenum support susceptor,we found that no significant changes were found in the center area of the plasma,but the electron state in the plasma changed greatly on the surface above the susceptor.The electron number density was reduced by about 40%,while the electron temperature was reduced by about 0.02 eV,and the concentration of atomic nitrogen was decreased by about an order of magnitude.Moreover,we found that if a specific lower microwave input power is used,and a susceptor structure without the small hole is introduced,the change results similar to those in the surface area of the susceptor will be obtained,but the spatial distribution of electromagnetic field and reactant concentration will be changed.展开更多
High quality, good adhesion and p-type diamond films are obtained by microwave plasma chelincal vapordeposition. The area of the films is 20 x 20 nun. The structural morphologies, bonding mechanism and surfacemol'...High quality, good adhesion and p-type diamond films are obtained by microwave plasma chelincal vapordeposition. The area of the films is 20 x 20 nun. The structural morphologies, bonding mechanism and surfacemol'Phology are characterized by X-ray diffraction (XRD), Raman scattering and scanning Electron microscopy(SEM) respectively. The resistance, Hall coefficient, mobility, etc. are also measured. Tile factors related tonucleation and other properties of diamond films are discussed.展开更多
文摘A novel plasma source suitable for controllable nanostructured thin film deposition processes is proposed. It exploits the separation of the process in two distinct phases. First precursor dissociation and radical formation is performed in a dense oxidizing plasma. Then nucleation and aggregation of molecular clusters occur during the expansion into vacuum of a supersonic jet. This allows a superior control of cluster size and energy in the process of film growth. Characterization of the plasma state and source performances in precursor dissociation have been investigated. The performances of this new Plasma Assisted Supersonic Jet Deposition technique were demonstrated using organic compounds of titanium to obtain TiO2 thin nanostructured films.
文摘The emission spectra of microwave plasma was in line measured in visible light wave band using a self made optical fiber spectrometer, the change rule of the atomic hydrogen ( H ) and double carbon radical( C 2) was given under different CH 4/H 2 ratios of volume flow. The effect of atomic hydrogen ( H ) on CVD diamond, deposited high quality and transparent diamond film by microwave plasma CVD (MPCVD) was analyzed according to the measured results by scanning electron microscopy(SEM), laser Raman spectrometry(Raman), and Fourier transform infrared spectrometry(FTIR). The results showed that the diamond film consisted of (220) orientation and it was homogeneous, compact, low defective, high quality film, its infrared transmissibility was about 70%, approached theoretical transmissibility of diamond. It was key conditions that a large number of atomic hydrogen ( H γ ) and double carbon radical( C 2) exist in the course of high quality diamond film growth. The research provided a rapid method for technology exploration of microwawe plasma CVD, and a reliable basis for research on growth mechanism of diamond film.
基金sponsored by National Key Research and Development Program of China(No.2019YFE03100200)National Natural Science Foundation of China(No.5210020483)+1 种基金Postdoc Research Foundation of Shunde Graduate School of University of Science and Technology Beijing(No.2020BH015)Fundamental Research Funds for the Central Universities(No.FRF-MP-20-48)。
文摘In this study,uniform diamond films with a diameter of 100 mm were deposited in a 15 kW/2.45 GHz ellipsoidal microwave plasma chemical vapour deposition system.A phenomenological model previously developed by our group was used to simulate the distribution of the electric strength and electron density of plasma.Results indicate that the electric field in the cavity includes multiple modes,i.e.TM_(02) and TM_(03).When the gas pressure exceeds 10 kPa,the electron density of plasma increases and plasma volume decreases.A T-shaped substrate was developed to achieve uniform temperature,and the substrate was suspended in air fromφ70 to 100 mm,thus eliminating vertical heat dissipation.An edge electric field was added to the system after the introduction of the T-shaped substrate.Moreover,the plasma volume in this case was greater than that in the central electric field but smaller than that in the periphery electric field of the TM_(02) mode.This indicates that the electric field above and below the edge benefits the plasma volume rather than the periphery electric field of the TM_(02) mode.The quality,uniformity and surface morphology of the deposited diamond films were primarily investigated to maintain substrate temperature uniformity.When employing the improved substrate,the thickness unevenness of theφ100 mm diamond film decreased from 22%to 7%.
基金financial support from the National Natural Science Foundation of China(Grant Nos.61974059,61674077,and 61774081)the Fundamental Research Funds for the Central Universities,China。
文摘This work proposed to change the structure of the sample susceptor of the microwave plasma chemical vapor deposition(MPCVD)reaction chamber,that is,to introduce a small hole in the center of the susceptor to study its suppression effect on the incorporation of residual nitrogen in the MPCVD diamond film.By using COMSOL multiphysics software simulation,the plasma characteristics and the concentration of chemical reactants in the cylindrical cavity of MPCVD system were studied,including electric field intensity,electron number density,electron temperature,the concentrations of atomic hydrogen,methyl,and nitrogenous substances,etc.After introducing a small hole in the center of the molybdenum support susceptor,we found that no significant changes were found in the center area of the plasma,but the electron state in the plasma changed greatly on the surface above the susceptor.The electron number density was reduced by about 40%,while the electron temperature was reduced by about 0.02 eV,and the concentration of atomic nitrogen was decreased by about an order of magnitude.Moreover,we found that if a specific lower microwave input power is used,and a susceptor structure without the small hole is introduced,the change results similar to those in the surface area of the susceptor will be obtained,but the spatial distribution of electromagnetic field and reactant concentration will be changed.
文摘High quality, good adhesion and p-type diamond films are obtained by microwave plasma chelincal vapordeposition. The area of the films is 20 x 20 nun. The structural morphologies, bonding mechanism and surfacemol'Phology are characterized by X-ray diffraction (XRD), Raman scattering and scanning Electron microscopy(SEM) respectively. The resistance, Hall coefficient, mobility, etc. are also measured. Tile factors related tonucleation and other properties of diamond films are discussed.
