【作者】 段磊；

【导师】 张以忱； 王庆；

【作者基本信息】 东北大学 ， 流体机械及工程， 2008， 硕士

【摘要】 根据磁控溅射反应的原理,由迟滞回线可以得出,要想获得较快的沉积速率和一定化学配比的高质量的薄膜,就要使磁控反应的位置在迟滞回线中的过渡区域,即在金属模式和化合模式之间拐弯点,而且迟滞回线具有不可逆性,这就要求有一种快速的反馈控制方法,自动控制反应气体的进入。有许多信号可以作为反馈信号和控制方法,通过对适应性和优劣点的比较,选择了等离子体发射光谱检测法。反应溅射镀膜机的PEM(plasma emission monitor)自动控制系统就是通过观测反应过程中等离子体发射光谱,由光谱图反映出来的真空室中各种粒子的密度来判断反应的状态,再根据反应的状态来自动控制反应气体的流量。理论上说,运用Stark等方法通过光谱图能够准确的计算出等离子体中各种粒子的密度,但是由于反应的复杂性和干扰参数的难确定性,得到的光谱强度与粒子密度有正比的关系,系统的控制部分就用粒子对应的相对光谱强度来反映各种粒子的相对密度。这中间需要用到光纤、光谱仪、光电转化等设备,这也是整个系统的重要部分。根据溅射镀膜机的工作原理和等离子体发射光谱诊断的原理,设计了能够根据反应状态快速调节反应气体质量流量的自动控制系统,应用于溅射镀膜机。对系统所用到的硬件设备进行了分析,并选择了光谱仪等主要设备的产品品牌和型号。对探头的安放位置、设备之间的接口等进行了分析说明。此外,对PEM控制器的调节参数的选择,控制算法和方式进行了分析研究,提出了利用同一条谱线不同反应状态的强度比值和不同种谱线强度的不同状态的比值,这两种选择调节参数的方式。设计了适用于反应溅射镀膜机PEM自动控制系统的单神经元自适应控制算法,并运用Matlab软件进行算法的仿真运算,通过与无自适应环节的传统PID算法进行对比,可以得到更加理想的控制效果。通过使用PEM控制系统,可以使反应磁控溅射镀膜机在沉积速率较高的情况下进行,并得到了质量更加优秀的化合物薄膜,提高了产品的应用价值。同时,该系统也是实际可行的。更多还原

【Abstract】 Based on the principle of reactive magnetron sputtering, what we can see from the hysteresis effect of reactive sputtering, we aim at getting high-grade film with high sputtering rate and optimum stoicheiometry, so we should set the reactive point in the transition region of the hystersis effect, which is between metallic mode and oxide mode. We know that hystersis effect is inerversible, so a fast control system is needed to make-up a closed loop to control the reactive gas flow. There are many signals can be used, we choose the PEM as the signal because of its adaptability.The PEM automatic control system of reactive sputtering coating equipment is monitoring the plasma with its emissions, and through the spectrogram the density of the different particles can be known and the state of reaction can be known too, than to control the reacting gas flow. On theory, we can compute the density of all the different particles exactly through the spectrogram with Stark manner etc. But because of the complexity and indeterminacy of parameters in reaction, with direct proportion between intensity of spectrum and density of particals, we choose the relative intensity of spectrum to agent the density of particals. And spectrometer, fiber, photoelectric conversion elements will be used in the system.Based on the principle of reactive magnetron sputtering and emission spectra diagnosing the plasma, I design an automatic system for reactive sputtering coating equipment which can adjust the react gas quickly. The equipments used in system are analysed, than the main equipments’brand and model number are chosen. The position of probe and interface of equipments are introduced.Furthermore, it formulates the regulation signal control algorithm and manners are studied. Two regulation signal modes are brought out with using the same or different spectral lines in different states. It designs a single neuron adaptive PID controller for PEM system of reactive sputtering coating equipment, and then simulates the control algorithm PID with software Matlab. By comparison simulation of classical PID without a single neuron adaptive controller, we can see it get a more ideal effect.Because of the PEM control system, the reactive sputtering coating equipment can work at the point with a high sputtering rate and get good compound thin film.Besides, the system is a fessible plan.更多还原