The optical emission spectra （atomic hydrogen （Hα, Hβ, Hγ）, atomic carbon C （2p3s → 2p^2： A = 165.7 nm） and radical CH （A^2△ →X^2П：λ = 420 - 440 nm）） in the gas phase process of the diamond film grow...The optical emission spectra （atomic hydrogen （Hα, Hβ, Hγ）, atomic carbon C （2p3s → 2p^2： A = 165.7 nm） and radical CH （A^2△ →X^2П：λ = 420 - 440 nm）） in the gas phase process of the diamond film growth from a gas mixture of CH4 and H2 by the technology of electron-assisted chemical vapor deposition （EACVD） have been investigated by using Monte Carlo simulation. The results show that the growth rate may be enhanced by the substrate bias due to the increase of atomic hydrogen concentration and the mean temperature of electrons. And a method of determining the mean temperature of electrons in the plasma in-situ is given. The strong dependence on substrate temperature of the quality of diamond film mainly attributes to the change of zas ohase orocess near the substrate surface.展开更多
Deposition parameters that have great influences on hot filament chemical vapor deposition (HFCVD) diamond films growth on inner hole surfaces of WC?Co substrates mainly include the substrate temperature (t), carbon c...Deposition parameters that have great influences on hot filament chemical vapor deposition (HFCVD) diamond films growth on inner hole surfaces of WC?Co substrates mainly include the substrate temperature (t), carbon content (φ), total pressure (p) and total mass flow (F). Taguchi method was used for the experimental design in order to study the combined effects of the four parameters on the properties of as-deposited diamond films. A new figure-of-merit (FOM) was defined to assess their comprehensive performance. It is clarified thatt,φandp all have significant and complicated effects on the performance of the diamond film and the FOM, which also present some differences as compared with the previous studies on CVD diamond films growth on plane or external surfaces. Aiming to deposit HFCVD diamond films with the best comprehensive performance, the key deposition parameters were finally optimized as:t=830 °C,φ=4.5%,p=4000 Pa,F=800 mL/min.展开更多
热丝化学气相沉积(Hot filament chemical vapor deposition,HFCVD)方法制备金刚石薄膜设备简单,成本低廉,适合大面积金刚石膜的产业化生产,其中衬底温度是沉积高质量CVD金刚石膜的重要参数之一。基于此,首先分析大面积HFCVD系统的热交...热丝化学气相沉积(Hot filament chemical vapor deposition,HFCVD)方法制备金刚石薄膜设备简单,成本低廉,适合大面积金刚石膜的产业化生产,其中衬底温度是沉积高质量CVD金刚石膜的重要参数之一。基于此,首先分析大面积HFCVD系统的热交换过程,建立大面积HFCVD系统衬底温度场的三维有限元模型。与传统纯热辐射模型相比,本模型更加接近实际系统,并较好符合试验测定的结果。根据三维有限元模型开展对大面积HFCVD系统衬底温度场的有限元仿真研究,得到HFCVD系统衬底温度场的三维分布规律,并讨论热丝直径、热丝温度、热丝根数、热丝-衬底距离和水冷散热系数等对衬底温度大小及均匀性的影响。仿真结果表明,在适宜金刚石膜生长的参数范围内,热丝参数和衬底接触热阻对衬底温度大小有显著影响,由于衬底内部的三维热传导使得衬底温度场更加均匀,各参数对衬底温度场的均匀性影响不大。研究结果为高质量制备金刚石膜提供理论基础。展开更多
基金the National Natural Science Foundation of China(No.10647123)the Youth Natural Science Foundation of Hebei University(No.2005Q31)
文摘The optical emission spectra （atomic hydrogen （Hα, Hβ, Hγ）, atomic carbon C （2p3s → 2p^2： A = 165.7 nm） and radical CH （A^2△ →X^2П：λ = 420 - 440 nm）） in the gas phase process of the diamond film growth from a gas mixture of CH4 and H2 by the technology of electron-assisted chemical vapor deposition （EACVD） have been investigated by using Monte Carlo simulation. The results show that the growth rate may be enhanced by the substrate bias due to the increase of atomic hydrogen concentration and the mean temperature of electrons. And a method of determining the mean temperature of electrons in the plasma in-situ is given. The strong dependence on substrate temperature of the quality of diamond film mainly attributes to the change of zas ohase orocess near the substrate surface.
基金Projects(51275302,51005154)supported by the National Natural Science Foundation of China
文摘Deposition parameters that have great influences on hot filament chemical vapor deposition (HFCVD) diamond films growth on inner hole surfaces of WC?Co substrates mainly include the substrate temperature (t), carbon content (φ), total pressure (p) and total mass flow (F). Taguchi method was used for the experimental design in order to study the combined effects of the four parameters on the properties of as-deposited diamond films. A new figure-of-merit (FOM) was defined to assess their comprehensive performance. It is clarified thatt,φandp all have significant and complicated effects on the performance of the diamond film and the FOM, which also present some differences as compared with the previous studies on CVD diamond films growth on plane or external surfaces. Aiming to deposit HFCVD diamond films with the best comprehensive performance, the key deposition parameters were finally optimized as:t=830 °C,φ=4.5%,p=4000 Pa,F=800 mL/min.
文摘热丝化学气相沉积(Hot filament chemical vapor deposition,HFCVD)方法制备金刚石薄膜设备简单,成本低廉,适合大面积金刚石膜的产业化生产,其中衬底温度是沉积高质量CVD金刚石膜的重要参数之一。基于此,首先分析大面积HFCVD系统的热交换过程,建立大面积HFCVD系统衬底温度场的三维有限元模型。与传统纯热辐射模型相比,本模型更加接近实际系统,并较好符合试验测定的结果。根据三维有限元模型开展对大面积HFCVD系统衬底温度场的有限元仿真研究,得到HFCVD系统衬底温度场的三维分布规律,并讨论热丝直径、热丝温度、热丝根数、热丝-衬底距离和水冷散热系数等对衬底温度大小及均匀性的影响。仿真结果表明,在适宜金刚石膜生长的参数范围内,热丝参数和衬底接触热阻对衬底温度大小有显著影响,由于衬底内部的三维热传导使得衬底温度场更加均匀,各参数对衬底温度场的均匀性影响不大。研究结果为高质量制备金刚石膜提供理论基础。
