高频半桥直流磁控溅射电源设计

稳定可靠的直流电源是直流磁控溅射镀膜质量的关键,本文采用开关频率为50 kHz的半桥拓扑,对主回路结构和参数进行设计.以SG3525控制芯片为核心,对控制回路按小信号模型建模,使用PI补偿网络,通过电阻负载实验得到稳定的直流.     

直流磁控溅射电源研制及输出特性研究

磁控溅射技术在薄膜制备领域广泛应用,电源是磁控溅射镀膜的关键设备之一.本文介绍了全桥逆变直流磁控溅射电源主电路和控制电路的设计,该电源输出功率2 kW,采用PI恒流控制,具有过流保护.通过阻性负载测试表明电源具有很好恒流特性,在输出功率超过400 W时电源效率比较高.利用氮气/氩气不锈钢靶直流磁控溅射实际的等离子体负载测试表明在保证真空室内压力不变的前提下,随着氮气比例的增加,电压下降,但电源恒流效果好,工作稳定.     

可调脉冲功率(MPP)磁控溅射电源研制及放电特性的研究

可调脉冲电源MPP(modulated pulsed power)磁控溅射技术是一种新型的高功率磁控溅射技术.基于STC12C5A60S2单片机为控制单元研制了MPP电源.电源可以输出多种脉冲波形,能够实现优化的高功率脉冲磁控溅射工艺.MPP放电模式表现为初始的弱放电和随后的高功率大电流放电行为.MPP放电电压影响着高功率放电电流和脉冲宽度,而放电气压主要影响起辉时刻,但对放电电流大小影响不大.引入引燃脉冲可实现低气压下的高功率大电流放电.     

高脉冲功率密度复合磁控溅射电源研制及放电特性研究

高功率脉冲磁控溅射技术(HPPMS)由于能够产生较高的离化率而受到人们的重视。为了提高离化率/沉积速率协同效应,基于直流和脉冲耦合叠加技术我们研制了高功率密度复合脉冲磁控溅射电源,并对高功率复合脉冲磁控溅射放电特性进行研究。结果表明脉冲峰值电流随脉冲电压的增加而增加,但随着脉冲宽度的增加而减小。在高功率脉冲期间工件上获得的电流可以增加一个数量级以上,表明磁控离化率得到显著增强。     

1kA高功率脉冲磁控溅射电源研制及试验研究

高功率脉冲磁控溅射(HPPMS)以其在真空镀膜上更大的优势而越来越受到重视,高压大电流电源是实现HPPMS的关键因素。本文研制了1000 A高功率脉冲磁控溅射电源,给出了电源框架图和主电路拓扑结构图。对脉冲部分采用仿真分析探索大模块IGBT的不均流因素,结果表明驱动一致性是影响均流的关键原因之一;分析了大电流时IGBT两端电压过冲问题,采用RCD吸收和续流回路能有效抑制电压过冲,使电压过冲在正常安全范围内。用所研制的电源进行等离子体负载实验,运行良好,为性能优异薄膜的制备奠定硬件基础。     

基于LCC谐振逆变器的中频磁控溅射电源在等离子体镀膜工艺中的应用

中频磁控溅射镀膜具有成膜均匀,膜重复性好,靶材不易中毒等诸多优点,适用于大规模生产,因此应用广泛。中频磁控溅射技术在电源的设计和应用方面非常重要,目前较为成熟的是正弦波和脉冲方波两种输出方式。本文阐述了正弦波输出方式的基于LCC谐振逆变器的中频磁控溅射电源的设计方法,并基于该电源的输出特性,分析该电源有利于提高镀膜工艺中的沉积效率,有利于抑制等离子体负载打弧,有利于等离子体负载特性匹配等优点。最后用正弦波输出方式的中频磁控溅射电源与脉冲方波输出方式的电源做了输出特性对比试验。     

基于FPGA的LCD显示控制器设计

文章介绍了图形式LCD视频控制芯片的设计方案,详细分析了该控制芯片的系统设计和各模块的功能实现,讨论并分析了模拟电路部分的设计,使用VHDL硬件描述语言完成了芯片数字部分的设计工作。LCD显示控制模块应用于示波表系统,为基于DSP、FPGA、LCD显示器协同工作的系统提供了一个较好的解决方案。     

基于FPGA汽车尾灯的设计

采用自顶向下的设计方法,介绍利用Verilog HDL硬件描述语言设计的汽车尾灯控制器的思路和技巧,在MAX+PLUSII开发环境中编译和仿真所设计的程序,并在FPGA芯片上下载验证。     

中频磁控反应溅射氧化硅（SiOx）薄膜绝缘性的研究

本文采用兆欧表测量电阻的方法,研究了中频磁控溅射氧化硅(SiO_x)薄膜的绝缘性。利用XRD和FTIR对薄膜进行了表征。结果表明：溅射产物为无定型SiO_x;兆欧表探针接触薄膜瞬间的电阻R_i与FTIR图谱位于900cm^-1波数附近的吸收峰a和760cm^-1附近的吸收峰b相关;随着R_i增加,吸收峰b红移,a与b的峰高比上升,SiO_x薄膜含氧量增大;R_i偏低的异常品经过250℃热处理,可达到正常产品的阻值范围,镀膜腔室内氧浓度的异常变化是生产过程中SiO_x薄膜绝缘性下降的原因。     

基于FPGA数控变频电源的设计

通过对PWM调制信号控制变频电源的分析研究,提出设计的基本方案,重点分析硬件设计和基于FPGA的数控部分的设计。这种设备的输出电压具有在一定范围内幅值、频率可调的优点,能最大限度满足用户对各种交流电源的需求。变频电源的核心技术是逆变控制系统,基于FPGA的逆变控制系统其实时性很强。     

Hysteresis-free reactive high power impulse magnetron sputtering

High power impulse magnetron sputtering (HIPIMS) of an Al target in Ar/O₂ mixtures has been studied. The use of HIPIMS is shown to drastically influence the process characteristics compared to conventional sputtering. Under suitable conditions, oxide formation on the target as the reactive gas flow is increased is suppressed, and the hysteresis effect commonly observed as the gas flow is varied during conventional sputtering can be reduced, or even completely eliminated, using HIPIMS. Consequently, stoichiometric alumina can be deposited under stable process conditions at high rates. Possible explanations for this behavior as well as a model qualitatively describing the process are presented.     

Mitigating the geometrical limitations of conventional sputtering by controlling the ion-to-neutral ratio during high power pulsed magnetron sputtering

High power pulsed magnetron sputtering has been used to grow thin chromium layers on substrates facing and orthogonal to the target. It is demonstrated that at low peak target current density, j_T < 0.6 A/cm² corresponding to a low ion-to-neutral flux ratio, films grown on substrates facing the target exhibit in-plane alignment. This is due to the rectangular shape of the target that yields an asymmetry in the off-normal flux of sputtered species. With increasing j_T the biaxial alignment degrades, as the major portion of the incoming flux (ions) can be effectively steered by the electric field of the substrate to remove asymmetry imposed by geometrical restrictions. Eventually, at j_T = 1.7 A/cm² a fiber texture is obtained. For films grown on substrates orthogonal to the target, the large column tilt characteristic for growth at low j_T, decreases with increasing ion content in the flux and almost disappears at the highest value of j_T. The latter indicates that material flux to the substrate is highly ionized so that deposition takes place along substrate normal despite the high nominal inclination angle. Thus, in the limit of high j_T the artifacts of conventional physical vapor deposition, resulting from the line-of-sight deposition, are effectively eliminated and the film growth proceeds more or less unaffected by the substrate orientation. Samples mounted orthogonally thus possess a similar texture, morphology, and topography as those facing the target.     

磁控溅射靶的磁路设计

磁控溅射是现代最重要的镀膜方法之一，具有简单，控制工艺参数精确和成膜质量好等特点。然而也有靶材利用率低、成膜速率低和离化率低等缺点。研究表明磁场结构对上述问题有重要影响，本文介绍了一种磁控溅射靶磁路优化设计方案。并对改进的磁场结构和一般的磁场结构进行了分析比较，并给出了实验结果。     

基于FPGA的高精度压电陶瓷数字驱动电源

 针对压电陶瓷驱动器在六自由度微动平台中的应用,研制了基于FPGA和PA85的六通道高精度数字驱动电源.该驱动电源分为D/A转换和高压线性放大两个模块,D/A转换模块将计算机发出的数字信号指令转换成模拟电压信号输出并进行初级低压放大,高压线性放大模块采用直流放大式电路,将经过初级放大的电压信号进行高压放大.实验结果表明,该驱动电源具有输出精度高、响应速度快、驱动能力强、稳定性好、结构简单、集成度高和调试方便等特点,能有效地应用于六自由度微动平台驱动中.     

Magnetron sputtering process control by medium-frequency power supply parameter

In this paper, the influence of the sputtering technology (reactive gas partial pressure, magnetic field intensity) on the power supply parameters has been investigated. The reactive sputtering of aluminium target in Ar + O₂ atmosphere has been used as an example. The experiments have shown that the formation of the Al₂O₃ layers can be observed by the parameter of the power supply. It allowed estimating the point at which the sputtered material surface was poisoned by the reactive compound i.e. distinguishing magnetron sputtering modes.     

高功率脉冲磁控溅射制备TiNx涂层研究

采用高功率复合脉冲磁控溅射技术(HPPMS)在316不锈钢、硬质合金基体上沉积了TiN薄膜,研究不同N2流量下TiNx膜层的沉积速率、硬度、晶体生长取向、摩擦磨损等性能,并在相同的平均靶电流下与直流磁控溅射制备的TiN薄膜对比.结果表明:HPPMS制备的膜层更加致密,在氩氮流量比为7.4∶1时膜层显微硬度达2470 HV,晶粒尺寸也明显小于直流磁控溅射制备的TiN,摩擦磨损性能也得到了改善.     

Hysteresis and process stability in reactive high power impulse magnetron sputtering of metal oxides

In the further development of reactive sputter deposition, strategies which allow for stabilization of the transition zone between the metallic and compound modes, elimination of the process hysteresis, and increase of the deposition rate, are of particular interest. In this study, the hysteresis behavior and the characteristics of the transition zone during reactive high power impulse magnetron sputtering (HiPIMS) of Al and Ce targets in an Ar-O₂ atmosphere as a function of the pulsing frequency and the pumping speed are investigated. Comparison with reactive direct current magnetron sputtering (DCMS) reveals that HiPIMS allows for elimination/suppression of the hysteresis and a smoother transition from the metallic to the compound sputtering mode. For the experimental conditions employed in the present study, optimum behavior with respect to the hysteresis width is obtained at frequency values between 2 and 4 kHz, while HiPIMS processes with values below or above this range resemble the DCMS behavior. Al-O films are deposited using both HiPIMS and DCMS. Analysis of the film properties shows that elimination/suppression of the hysteresis in HiPIMS facilitates the growth of stoichiometric and transparent Al₂O₃ at relatively high deposition rates over a wider range of experimental conditions as compared to DCMS.     

磁控溅射膜层厚度均匀性测试

在相对于平面磁控溅射阴极均匀区范围内安放硅片，镀膜后进行膜层厚度测试，然后计算膜层厚度均匀度。结果，片间厚度均匀性为1％～-1．7％；炉间厚度均匀性为3．5％～-2％。     

PEM控制中频孪生反应磁控溅射沉积TiO2薄膜的研究

在中频孪生靶反应磁控溅射实验装置上,用PEM控制沉积TiO2薄膜,实验了靶基距、电流与沉积速率的关系。实验得出,靶基距为112 mm时沉积速率最大,沉积速率与电流基本成线性比例关系。在溅射电流30 A,靶基距112 mm,设置点2.5时,测量了基片随时间的温升变化。然后以自然温升的单晶硅为基片,实验研究了设置点对TiO2薄膜晶体结构、折射率的影响。实验结果表明,设置点越高溅射沉积的薄膜金红石相越多,折射率也越高。