等离子体刻蚀工艺的优化研究

本文基于对硅的等离子刻蚀(RIE)工艺参数的研究,得出了刻蚀速率与射频功率、刻蚀气体压强和刻蚀气体流量之间的关系曲线[1],优化了刻蚀硅的工艺条件。通过台阶仪的测量,实验结果表明优化工艺条件下的硅化物的刻蚀具有较高的刻蚀速率和较高的选择比。     

平板电极间鞘层离子刻蚀速率计算

利用所建立的鞘层区离子速度分布函数，得出了鞘层区离子平均能量、平均速度、和通量以及高能中性粒子通量和能量通量等数学模型。计算了包括离子和高能中性粒子的刻蚀速率，结果表明与实验数据吻合。各模型都以工艺参数：压力、温度、放电电压以及反应室尺寸等参数表示，为工艺优化提供了理论依据。     

粉尘等离子体的研究

在实验和理论上研究了粉粒在等离子体鞘区的沉降、带电、收集和刻蚀。基于粉尘对等离子区电子能量分布函数的影响,讨论了粉尘对等离子体的干扰。有关结果表明等离子体对硅粉的纯化处理有可能应用于将工业硅直接制成太阳级硅。     

巨磁电阻多层结构——从多层膜到多层纳米线

综述了巨磁电阻多层膜（包括连续多层膜,不连续多层膜,颗粒膜,非匀相合金膜及层状与粒状混合型多层膜）研究的一些结论,着重评述了巨磁电阻多层纳米线的研究进展,包括其制备,表征,传输性能的测定方法,电流垂直于膜面的巨磁电阻（CPP－GMR）,及如何利用多层纳米线的CPP－GMR测定材料的自旋扩散长度和自旋散射不对称因子等材料常数。简要介绍了开发前景。     

射频等离子体放电的宏观参数与PET表面改性的关系

通过射频等离子体放电，采用Ｏ２，ＣＦ４及ＣＨ４／ＣＦ４混合气体等离子体对ＰＥＴ表面进行处理。改变射频等离子体放电的宏观参数，如放电时间，放电功率，电极间距离和复合参数，详细地研究了这些参数对ＰＥＴ表面改性的影响。结果表明：碳氟混合气体等离子体在ＰＥＴ表面的沉积速率为正值，在ＰＥＴ表面形成了聚合物，而Ｏ２和纯ＣＦ４气体的沉积速率为负值，两者在ＰＥＴ表面产生刻蚀效应。     

深蚀刻玻璃光波导光栅的研究

采用全息法制备了光刻胶光栅，并用该光栅掩膜离子蚀刻，刻得槽深为１．６μｍ的玻璃光栅，再采用Ｋ＾＋／Ｎａ＾＋交换法制备玻璃光波导光栅，用６３３ｎｍ波长激光由一端棱镜耦合输入，经过光栅，由另一端面输出，在实验中观察到多级布拉格衍射，一级布拉格衍射效率最高达９０％。     

塑料薄膜的多层复合技术

复合薄膜材料由于其优异的综合性能已经在各大领域得到了广泛的应用,而其成型的关键即多层复合技术近年来得到了快速的发展.本文就该技术进行了综述.     

多层印制板生产中非金属材料的保护技术

对多层印制板生产中的阻焊膜保护技术进行了详细阐述。对阻焊膜制作的工艺过程，工序过程质量控制，产品质量问题的产生原因及采取的相应对策进行了简要介绍。     

射频等离子体放电的宏观参数与PET表面改性的关系

通过射频等离子体放电，采用O2，CF4及CH4／CF4混合气体等离子体对PET表面进行处理。改变射频等离子体放电的宏观参数，如放电时间、放电功率、电极间距离和复合参数，详细地研究了这些参数对PET表面改性的影响。结果表明：碳氟混合气体等离子体在PET表面的沉积速率为正值，在PET表面形成了聚合物；而O2和纯CF4气体的沉积速率为负值，两者在PET表面产生刻蚀效应。增加等离子体放电功率和放电时间，聚合或刻蚀效果更明显；而增加电极间距离和复合参数，聚合或刻蚀效果明显减弱。     

牺牲层刻蚀实验的在线观察与研究

设计了多种测试结构，采用在线实时观测的手段，深入研究了氢氟酸（HF）刻蚀二氧化硅牺牲层中，多种因素对刻蚀过程产生的影响，并对实验结果进行了详细分析．实验中可以明显观察到刻蚀过程中的反应限制阶段与扩散限制阶段，说明经过长时间的刻蚀，HF酸的扩散效应将成为影响刻蚀速率的主导因素．对于实验过程中观察到的“凹”状的刻蚀前端和“晕纹”现象，分析认为结构中的应力梯度以及材料间不同的亲水性质是产生这些现象的主要原因．实验方法与结论对MEMS牺牲层释放工艺的研究具有一定的参考意义．     

ICP刻蚀技术在808nm激光器中的应用

主要分析了不同工艺参数对于刻蚀图形的影响，包括刻蚀侧壁角度，刻蚀表面平整度，选择比，侧向钻蚀等几个方面，及ICP刻蚀对激光器性能的影响，通过对翔蚀图形的控制，使2寸片内均匀性〈±5％，侧壁角达到79°～81°。     

Silicon Wafer Surface-Temperature Monitoring System for Plasma Etching Process

A thermoreflectance temperature measuring system was developed with the aim to realize monitoring of the silicon wafer surface temperature during plasma etching. The thermoreflectance detects variations in temperature through changes in optical reflectance. To overcome such difficulties as low sensitivity and limitation in installation space and position for in situ measurements, the differential thermoreflectance utilizing two orthogonal polarizations was introduced. Noise such as fluctuations in the incident beam intensity or changes of loss in the optical path would affect both polarizations equally and would not affect the measurement. The large angle of incidence of the beam allows measurement to be performed from outside the viewing ports of existing plasma etching process chambers through the gap between the plasma electrode and the silicon wafer. In this article, an off-line measurement result is presented, with results for bare wafers as well as for wafers with metal depositions. A prototype system developed for tests in plasma etching facilities in a production line is described.     

Advanced Power Supplies designed for Plasma Deposition and Etching

Plasma deposition and etching processes are used for a wide range of applications as for example the production of semiconductor circuits, flat panel displays, solar cells, architectural glass and data storage media. To fulfill the special needs of each single process stable DC, MF and RF process power ranging from 50W to 200kW is needed. All generators need a high precision process control and a supreme arc management with adaptable parameters to provide minimal disturbances in the plasma process and to obtain optimized results in terms of film quality, homogeneity and uniformity over the whole substrate. The fast and flexible arc handling leads to an improvement in the film quality by minimizing flaws and defects and enables the use of very high sputter rates. To fit DC process demands a new concept for a modular DC system has been realized where up to four 30kW modules can be combined using master slave concept. The arc management and control of the DC module has an intelligent control enabling arc detection times of less than 1μs and a residual energy delivered to the process of only 6 mJ per kW. For MF processes a fast and effective arc management is an even more important tool for keeping reactive processes stable. The new generation of MF power supplies enables arc detection and shut off times of 5μs with a residual energy delivered to the process of only 5 mJ per kilowatt. This yields the additional advantage that even when the cathode material is almost used up and consequently the arc probability increases, the low residual energy values contribute to an extended service life of the cathode and to better utilization of the target material. Essentially, the outstanding feature of effective arc management is an undisturbed plasma during the whole operation time. The fast arc suppression minimizes the interruption in the sputtering process to negligibly small values. However, because arcs also serve to remove unwanted materials on the cathode, power supplies must be able to control and regulate the arc energy precisely. MF power supplies are available for process power up to 200kW. RF systems are based on two different concepts to fit the broad power range between 50W and 50kW. For the low energy range a fully transistorized and μC‐controlled RF generator was developed. This generator has been designed for a max. power of 3kW. Important features are the compact size, robustness, reliability and easy maintenance To have a cost effective design for a high power RF generator in this power range an oscillator ‐ amplifier concept has been chosen with a solid state driver in combination with a tube type end stage amplifier. To fit todays demands for advanced etching a dual frequency system consisting of a 13.6 MHz and a 3.4 MHz unit was developed. This enables the possibility to separately control plasma density and ion energy of the discharge.     

用于扫描刻蚀加工的微小等离子体反应器的设计和实验

提出了一种新的基于并行探针的扫描等离子体刻蚀加工方法,设计并研制了其中的核心器件--微小等离子体反应器,测量了该器件的伏安特性曲线,分析了其电学性能随工作气压和器件尺寸的变化规律,以及器件损坏的机制.实验结果表明,当放电气体为SF6,工作气压在2 000～6 000 Pa之间变化时,该器件能产生较为稳定的微等离子体,放电电压在390～445 V之间,功率密度在10～150 W/cm^2之间,从而为进一步将其应用到扫描硅刻蚀加工提供可能.     

微波ECR等离子体刻蚀系统

研制成功了一台微波电子回旋共振等离子体刻蚀系统。该系统采用微波通过同轴开口电介质空腔产生表面波 ,由Nd Fe B永磁磁钢形成高强磁场 ,通过共振磁场区域内的电子回旋共振效应产生大面积、均匀、高密度等离子体。利用该系统实现了SiO2 、SiN、SiC、Si等材料的微细图形刻蚀 ,刻蚀速度分别为 2 0 0nm/min ,5 0 0nm/min ,4 0 0nm/min ,70 0nm/min ,加工硅圆片Φ2 0 0mm ,线条宽度 <0 3μm ,选择性 (SiO2 、Si) >2 0 ,剖面控制 >83° ,均匀性 95 % ,等离子体密度 2 0× 10 11cm-3 。电离度大(>10 % ) ,工作气压低 (1Pa～ 10 -3 Pa) ,均匀性好 ,工艺设备简单 ,参数易于控制等优点。     

等离子体刻蚀的数学模型

介绍了等离子体刻蚀中的三种主要的数学模型 ,即 :物理模型、反应表面模型、神经网络模型。简要地叙述了它们的原理和优缺点。     

ICP刻蚀4H-SiC栅槽工艺研究

为避免金属掩膜易引起的微掩膜,本文采用SiO2介质作为掩膜,SF6/O2/Ar作为刻蚀气体,利用感应耦合等离子体刻蚀(ICP)技术对4H-SiC trench MOSFET栅槽刻蚀工艺进行了研究。本文详细研究了ICP刻蚀的不同工艺参数对刻蚀速率、刻蚀选择比以及刻蚀形貌的影响。实验结果表明:SiC刻蚀速率随着ICP功率和RF偏压功率的增大而增加;随着气体压强的增大刻蚀选择比降低;而随着氧气含量的提高,不仅刻蚀选择比增大,而且能够有效地消除微沟槽效应。刻蚀栅槽形貌和表面粗糙度分别通过扫描电子显微镜和原子力显微镜进行表征,获得了优化的栅槽结构,RMS表面粗糙度0.4nm。     

ICP深硅刻蚀工艺研究

感应耦合等离子体(ICP)刻蚀技术是微机电系统器件加工中的关键技术之一.利用英国STS公司STS Multiplex刻蚀机,研究了ICP刻蚀中极板功率、腔室压力、刻蚀/钝化周期、气体流量等工艺参数对刻蚀形貌的影响,分析了刻蚀速率和侧壁垂直度的影响原因,给出了深硅刻蚀、侧壁光滑陡直刻蚀和高深宽比刻蚀等不同形貌刻蚀的优化工艺参数.