等离子体性状对CVD金刚石沉积结果影响的研究
发布时间：2019-05-15 23:19
【摘要】：本文综述了直流电弧喷射等离子体增强化学气相沉积(DC Acjet plasma enhanced CVD)金刚石技术的发展历史和研究现状,明确提出了等离子体性状在CVD金刚石过程中是影响沉积物形貌、质量和生长速度的重要因素的观点。 采用大功率直流电弧喷射等离子体沉积设备,制备了多晶金刚石自支撑膜,包括微米晶、纳米晶、超纳米晶自支撑膜。利用扫描电镜、拉曼光谱、X射线衍射仪以及透射电镜,研究了所制备多晶膜体的形貌、质量以及晶体学性质,发现了CVD金刚石膜生长面的一种“菠萝状”新形貌,这种形貌是由纳米晶构成的、各个纳米晶粒之间存在着无定形碳,占优晶面为(100)晶面,这是金刚石膜体从微米晶向纳米晶过渡时的一种中间态形貌,同时实验结果也表明,等离子体的不同部位在衬底上会形成不同的沉积区。 利用光发射谱(OES)诊断了直流电弧喷射等离子体的成分,研究了等离子体成分在沉积区域的空间分布和在沉积时间内的浓度演化。实验结果显示不同基元的光发射存在固定的峰位,虽然强度会随着反应气体的流量比不同而发生变化,但是同种基元的谱峰形状和谱峰位置不变,这表明直流电弧喷射等离子体具有稳定的等离子体成分。通过开发精细OES方法,对近生长表面的等离子体也进行了诊断,结果发现：在沉积区域内,等离子体中各基元的光发射强度会随着空间位置的不同而不同,其中距离沉积面的高度对光发射强度的影响最大,当距离超过5毫米后,光发射强度变化不大,但是在近表面5mm以下时,光发射强度变化显著。等离子体中的基元光发射强度随时间的延长会发生波动,当沉积时间小于30小时,C2与CH光发射强度的比值近似等于2.08,超过30小时,C2与CH光发射强度的比值会单调增加。 利用计算机模拟分析技术模拟了不同参数下的等离子体流动特性,包括流场、温度场、压力场。模拟结果显示,在衬底近表面的等离子体可以分为两个区域,一个是滞止区,一个是沿壁射流区。在射流距离一定时,随着射流速度加大,滞止区变小,同时沿壁射流区的边界层厚度也减小；在射流速度一定时,随着射流距离的增大,滞止区变大,沿壁射流区的边界层变厚。当射流速度一定时,温度场随着射流距离变大而变得不均匀,当射流距离一定时,温度场又会随射流速度变大而变得均匀。滞止区压力最大,在沿壁射流区压力会随着距离的变长而减小。 研究了直流电弧技术在高CH4/H2条件下的同质形核孕育期。利用FIB、 TEM、HREM、EELS等离线技术分析了在多晶金刚石上进行金刚石早期沉积的情况,发现金刚石形核之前存在一个非晶碳层,随后金刚石的晶核在这层非晶碳中形成,形成的晶核尺寸在2-3nm左右。根据模拟计算结果,设定了精细OES的测量点,结果表明在大碳氢比条件下的金刚石沉积早期,边界层中的C2基元的光发射强度会发生变化,在一定时间中会有明显的波动现象。结合离线技术的检测结果,可以判明这些波动与金刚石的形核有关。根据OES的结果可以推断,在大的FCH4/FH2条件下(15%),CVD金刚石的形核孕育期在6-8分钟,且随着FCH4/FH2增大,孕育期缩短。OES的结果同时也表明,在金刚石衬底上的形核是爆发式的形核。 在天然金刚石的(100)面上采用“定态”和“动态”两种生长模式制备了毫米级单晶金刚石颗粒,其中“定态”生长模式工艺简单,但是籽晶的装夹方式是保证生长能否继续的关键因素。“动态”生长模式可以通过改变衬底沉降速度来操控生长速度,单晶的生长速度随着衬底沉降速度的增加而增加,但是过快的衬底沉降速度会导致由应力诱导的ATG型形貌,进而引发多晶生长。在“动态”生长模式中,单晶的生长速度可以达到52μm/h。
[Abstract]:In this paper, the development history and research status of DC-arc plasma enhanced chemical vapor deposition (DC Acjet plasma enhanced CVD) diamond technology are reviewed, and the effects of plasma character on the morphology of the deposit in the process of CVD diamond are put forward. An important factor in the quality and speed of growth. the polycrystalline diamond self-supporting film is prepared by adopting a high-power direct current arc spraying plasma deposition equipment, The morphology, quality and crystallography of the prepared polycrystalline film were studied by means of scanning electron microscope, Raman spectrum, X-ray diffractometer and transmission electron microscope. And the experimental results also show that different parts of the plasma form different deposition on the substrate. In this paper, the spatial distribution of the plasma components in the deposition area and the concentration of the plasma in the deposition time are studied by using the light emission spectrum (OES) to diagnose the components of the DC arc spray plasma. The experimental results show that the light emission of different elements has a fixed peak, although the intensity changes with the flow rate of the reaction gas, the spectral peak shape and the spectral peak position of the same cell do not change, which indicates that the DC arc spray plasma has a stable plasma. By developing the fine OES method, the plasma of the near-growing surface is also diagnosed. The results show that in the deposition area, the light emission intensity of the elements in the plasma varies with the spatial position, and the height of the distance deposition surface is the shadow of the light emission intensity. In response to the maximum, when the distance exceeds 5 mm, the intensity of the light emission is not large, but when the near surface is less than 5 mm, the light emission intensity changes And the ratio of C2 to CH light emission intensity is approximately equal to 2.08 when the deposition time is less than 30 hours, and the ratio of the C2 to the CH light emission intensity is single. The characteristics of plasma flow under different parameters are simulated by computer simulation and analysis, including flow field, temperature, The simulation results show that the plasma in the near surface of the substrate can be divided into two areas, one is the stagnation zone, one is along the wall-jet area, as the jet velocity increases, the stagnation area becomes smaller, and the thickness of the boundary layer along the wall-jet area is also reduced; at the same time, as the jet velocity is constant, the stagnation-stopping area is larger with the increase of the distance of the jet, and along the wall-jet area, The boundary layer is thickened. When the velocity of the jet is constant, the temperature field becomes non-uniform with the distance of the jet, and when the distance of the jet is constant, the temperature field will increase with the velocity of the jet. And the pressure of the stagnation zone is the largest, and the pressure in the jet zone along the wall will follow the distance. The effect of direct current arc in the condition of high CH4/ H2 is studied. The early deposition of the diamond on the polycrystalline diamond was analyzed by using an off-line technique such as FIB, TEM, HREM, and EELS. It was found that there was an amorphous carbon layer before the nucleation of the diamond, and then the crystal nucleus of the diamond was formed in the amorphous carbon, and the crystal nucleus was formed. The measurement points of fine OES are set according to the results of the simulation. The results show that in the early stage of diamond deposition under the condition of large hydrocarbon ratio, the light emission intensity of the C2 elements in the boundary layer will change, and there will be some time. Obviously, the fluctuation and gold can be determined by combining the detection results of off-line technology. Based on the results of the OES, it is concluded that the nucleation and incubation period of CVD diamond is 6-8 minutes under the condition of large FCH4/ FH2 (15%), and with the increase of FCH4/ FH2 The results of OES also show that nucleation on the diamond substrate The surface of the natural diamond (100) adopts two growth modes of "fixed state" and "dynamic" to prepare the millimeter-grade single crystal diamond particles, wherein the "fixed state" growth mode is simple in process, but the clamping mode of the seed crystal is to ensure the growth The dynamic "growth mode can control the growth rate by changing the settling velocity of the substrate, and the growth speed of the single crystal is increased with the increase of the settling speed of the substrate, but too fast the settling speed of the substrate can lead to the ATG-type morphology induced by the stress. in a "dynamic" growth mode, that growth rate of the single crystal may
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TQ163
本文编号：2477842
[Abstract]:In this paper, the development history and research status of DC-arc plasma enhanced chemical vapor deposition (DC Acjet plasma enhanced CVD) diamond technology are reviewed, and the effects of plasma character on the morphology of the deposit in the process of CVD diamond are put forward. An important factor in the quality and speed of growth. the polycrystalline diamond self-supporting film is prepared by adopting a high-power direct current arc spraying plasma deposition equipment, The morphology, quality and crystallography of the prepared polycrystalline film were studied by means of scanning electron microscope, Raman spectrum, X-ray diffractometer and transmission electron microscope. And the experimental results also show that different parts of the plasma form different deposition on the substrate. In this paper, the spatial distribution of the plasma components in the deposition area and the concentration of the plasma in the deposition time are studied by using the light emission spectrum (OES) to diagnose the components of the DC arc spray plasma. The experimental results show that the light emission of different elements has a fixed peak, although the intensity changes with the flow rate of the reaction gas, the spectral peak shape and the spectral peak position of the same cell do not change, which indicates that the DC arc spray plasma has a stable plasma. By developing the fine OES method, the plasma of the near-growing surface is also diagnosed. The results show that in the deposition area, the light emission intensity of the elements in the plasma varies with the spatial position, and the height of the distance deposition surface is the shadow of the light emission intensity. In response to the maximum, when the distance exceeds 5 mm, the intensity of the light emission is not large, but when the near surface is less than 5 mm, the light emission intensity changes And the ratio of C2 to CH light emission intensity is approximately equal to 2.08 when the deposition time is less than 30 hours, and the ratio of the C2 to the CH light emission intensity is single. The characteristics of plasma flow under different parameters are simulated by computer simulation and analysis, including flow field, temperature, The simulation results show that the plasma in the near surface of the substrate can be divided into two areas, one is the stagnation zone, one is along the wall-jet area, as the jet velocity increases, the stagnation area becomes smaller, and the thickness of the boundary layer along the wall-jet area is also reduced; at the same time, as the jet velocity is constant, the stagnation-stopping area is larger with the increase of the distance of the jet, and along the wall-jet area, The boundary layer is thickened. When the velocity of the jet is constant, the temperature field becomes non-uniform with the distance of the jet, and when the distance of the jet is constant, the temperature field will increase with the velocity of the jet. And the pressure of the stagnation zone is the largest, and the pressure in the jet zone along the wall will follow the distance. The effect of direct current arc in the condition of high CH4/ H2 is studied. The early deposition of the diamond on the polycrystalline diamond was analyzed by using an off-line technique such as FIB, TEM, HREM, and EELS. It was found that there was an amorphous carbon layer before the nucleation of the diamond, and then the crystal nucleus of the diamond was formed in the amorphous carbon, and the crystal nucleus was formed. The measurement points of fine OES are set according to the results of the simulation. The results show that in the early stage of diamond deposition under the condition of large hydrocarbon ratio, the light emission intensity of the C2 elements in the boundary layer will change, and there will be some time. Obviously, the fluctuation and gold can be determined by combining the detection results of off-line technology. Based on the results of the OES, it is concluded that the nucleation and incubation period of CVD diamond is 6-8 minutes under the condition of large FCH4/ FH2 (15%), and with the increase of FCH4/ FH2 The results of OES also show that nucleation on the diamond substrate The surface of the natural diamond (100) adopts two growth modes of "fixed state" and "dynamic" to prepare the millimeter-grade single crystal diamond particles, wherein the "fixed state" growth mode is simple in process, but the clamping mode of the seed crystal is to ensure the growth The dynamic "growth mode can control the growth rate by changing the settling velocity of the substrate, and the growth speed of the single crystal is increased with the increase of the settling speed of the substrate, but too fast the settling speed of the substrate can lead to the ATG-type morphology induced by the stress. in a "dynamic" growth mode, that growth rate of the single crystal may
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TQ163
【参考文献】
相关期刊论文 前10条
1 陈旭宏,赵立合,吕反修;直流等离子体喷射镀膜设备的传热数学模型[J];北京科技大学学报;1999年01期
2 钟国仿,申发振,唐伟忠,吕反修;基片温度对直流电弧等离子体喷射沉积金刚石膜的影响[J];北京科技大学学报;1999年04期
3 黄天斌,唐伟忠,吕反修,张维敬;大面积金刚石膜生长环境气氛的计算机模拟[J];北京科技大学学报;2000年02期
4 安希忠,张禹,刘国权,秦湘阁,王辅忠,刘胜新;CVD金刚石膜｛100｝取向生长的原子尺度仿真[J];北京科技大学学报;2002年02期
5 吕反修;;大面积光学级金刚石自支撑膜制备、性能及其在高技术领域应用前景[J];中国表面工程;2010年03期
6 王传新,汪建华,马志斌,满卫东,王升高,康志成,吴素娟;低偏压下化学气相沉积金刚石薄膜的生长形貌研究[J];材料保护;2003年05期
7 黄建良;汪建华;;CVD金刚石薄膜的形核研究[J];材料导报;2007年S2期
8 王兵,梅军,李力,季锡林,冉均国,苟立;CVD金刚石膜产业化制备技术研究[J];材料科学与工艺;2003年01期
9 黄元盛,刘正义,邱万奇;CVD金刚石薄膜二次形核机制的研究[J];材料科学与工程;2001年01期
10 唐壁玉,靳九成,陈宗璋;CVD金刚石成核的最新研究[J];材料开发与应用;1998年06期
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