基于Petri网与遗传算法的半导体生产线建模与优化调度

针对半导体生产线调度复杂、难以优化的问题,本文提出了一种基于层次有色赋时Petri网技术和遗传算法相结合的优化调度方法。该方法利用层次化的方法结合自顶向下建模方法对半导体生产线进行模块化建模,模型不仅能够反映生产线的待加工产品的多条加工路径及其资源约束,还可以对系统的设备维护、各种优先级等特性进行描述,得到对生产系统更完善更精确的刻画。通过在遗传算法编码中同时考虑投料策略、工件选设备规则、批加工调度规则和单件加工设备规则等因素得到更加有效的调度方案,提高了模型的优化程度。在此基础上,对实际半导体生产线的不同调度方案分别进行了仿真,并对仿真结果进行了比较,从而验证了建模方法的正确性及调度策略的有效性。     

半导体设备预测性维修技术

预测性维修是多年来维修领域研究的重点问题,文章从一般预测维修的论点出发,分析比较了修复性维修、预防维修和预测性维修的优缺点,并列举了一些半导体设备预测性维修的措施。半导体设备生产都是流水线作业,生产中任何一台设备发生故障或者失败都会给企业带来停产,造成巨大损失。所以要对重点设备、关键设备进行监控,进行预知性维修,消除隐藏故障,避免发生重大灾难后果。预测性维修是以状态为依据的维修,在机器运行时,对它的主要部位进行定期(或连续)的状态监测和故障诊断,判定装备所处的状态,预测装备状态未来的发展趋势,依据装备的状态发展趋势和可能的故障模式,预先制定预测性维修计划,确定机器启动修理的时间、内容、方式和必需的技术及物资支持。预测性维修集设备状态监测、故障诊断、故障(状态)预测、维修决策支持和维修活动于一体,是一种新兴的维修方式。     

Closed-loop measurement of equipment efficiency and equipmentcapacity

Formal definitions for the components of efficiency and capacity, mathematical formulas for computing overall efficiency, and data collection strategies are proposed for rigorous measurement of equipment efficiency and equipment capacity. Measurement of overall equipment efficiency (OEE) under the TPM paradigm is extended to support the maintenance of capacity parameters for production planning. The weaknesses or equipment analyzes based on utilization and aggregate UPH (units per hour) figures are contrasted against the robustness of the proposed approach. Applications in semiconductor factories are discussed     

Intelligent prognostics system design and implementation

This paper proposes an intelligent prognostics system JPS) for semiconductor and TFT-LCD manufacturing. The IPS comprises several generic embedded devices (GEDs) and remote clients. The GED can be easily embedded into various types of equipment to acquire equipment engineering data and meet the specification requirements of Interface A for supporting semiconductor industry equipment engineering capabilities. Furthermore, the GED has an open-standard application interface offering pluggable and customized intelligent applications. With this feature, the intelligent applications can be distributed and localized, releasing the factory network burden and enhancing equipment reliability and processing quality. This paper also develops two typical pluggable applications: the predictive maintenance scheme (PMS) for detecting equipment faults and the virtual metrology scheme (VMS) for conjecturing equipment-processing quality. Integrating the PMS into the IPS and the VMS into the IPS are, respectively, accomplished using the conveyor equipment and the sputtering equipment in a TFT-LCD factory. These two illustrative examples clearly demonstrate that IPS is versatile, configurable, and effective.     

半导体晶圆制造中的设备效率和设备能力

在半导体制造车间中,设备是非常昂贵的,设备折旧与维修占生产成本组成的最大比重,设备利用率的提高显得尤为重要,因此设备效率和设备能力已成为半导体制造者最关心的问题之一.本文针对该问题,系统地介绍了半导体晶圆制造中设备效率和设备能力的衡量标准及其数据收集,以期达到提高设备利用率的目的.     

Continuous equipment diagnosis using evidence integration: an LPCVDapplication

A diagnostic system that employs the Dempster-Shafer (D-S) evidential reasoning technique to conduct malfunction diagnosis on semiconductor manufacturing equipment has been developed. This is accomplished by combining the continuous stream of information that originates from maintenance status records, from real-time sensor measurements, and from the differences between inline measurements and values predicted by equipment models. Using this information, equipment malfunctions are analyzed and their causes are inferred through the resolution of qualitative and quantitative constraints. The qualitative constraints describe the normal operation of the equipment. The quantitative constraints are numerical models that apply to the manufacturing step in question. These models are specifically created and characterized through experimentation and statistical analysis, and they can be updated to reflect equipment aging. The violation of these constraints is linked to the evaluation of continuous belief functions for the calculation of the belief associated with the various types of failure. The belief functions encapsulate the experience of many equipment maintenance specialists. Once created, the belief functions can be fine-tuned automatically, drawing from historical maintenance records. These records are stored in symbolic form to facilitate this task, and they must be updated to track equipment changes over time. A prototype of this diagnostic system was implemented in an object-oriented programming environment. The effectiveness of this technique was demonstrated on a low-pressure chemical vapor deposition (LPCVD) reactor used for the deposition of undoped polysilicon     

利用WinSock实现半导体封装设备的通信

Socket接口是TCP/IP的API,TCP/IP网络中的应用程序,是通过Socket实现的.WinSock是一套开放的、支持多种协议的Windows下的网络编程接口.介绍了利用WinSock进行网络编程的一般方法,并在此基础上解决了半导体封装设备使用TCP/IP协议进行网络实时通信的问题,实现了在服务器和客户机两端准确方便地实时发收文件和互相通信,并测试了发收不同大小文件所消耗的平均时间.     

2006/2007年全球半导体设备市场

预测了2006/2007年全球半导体市场及半导体设备市场。2006年全球半导体市场增长率为8%～11%,2007年为10%～11%。2006年全球半导体设备市场增长率为18%,2007年为10%以上。2006年中国半导体市场增长率为30%,2007年为31%。2006年中国半导体设备市场增长率为78.11%,2007年为1%。     

Reliability of semiconductor lasers used in current communication systems and sensing equipment

The degradation mechanisms that had occurred – but that have now been largely suppressed or eliminated – in established consumer equipment and optical communication systems have also become problems in current optical fiber communication systems. This is due to the requirements of recently developed communication systems for semiconductor lasers, which operate at higher performance levels under severe environmental conditions. In addition, semiconductor lasers have now become important optical sources in new application fields such as sensing equipment, and these new applications have in turn brought new reliability problems to semiconductor lasers. In this paper, the degradation modes and reliability of semiconductor lasers are reviewed and discussed in association with recently developed optical sensing equipment and communication systems.     

Quantifying the environmental footprint of semiconductor equipment using the environmental value systems analysis (EnV-S)

Many environmental and health impacts from semiconductor processing are tied to the design of the manufacturing equipment. Evaluating solutions to properly treat effluents from semiconductor tools has become an increasingly important part of supply chain management and equipment procurement decisions. Accordingly, understanding the environmental footprint associated with equipment sets is essential for both equipment manufacturers and semiconductor manufacturers seeking to improve their products' environmental and financial performance. Equipment environmental performance must be evaluated within the context of the factory infrastructure and auxiliary equipment sets, with appropriate allocations of impacts from additional steps, both upstream and downstream of the wafer processing tools (chemical precursor delivery as well as byproduct treatment). Several challenges to environmental assessments arise from the nature of semiconductor manufacturing itself, due to short process life cycles, complexity of processes, and the need to track diverse inter-related impacts. Environmental value systems analysis (EnV-S) is an analytical tool to evaluate the environmental performance of semiconductor processing. EnV-S develops environmental assessments through a "bottom-up" analysis approach, assembling equipment environmental models to describe a system. This paper presents the use of EnV-S as a tool to quantify the environmental impact of a product or process by creating an operational signature along multiple dimensions of cost and environmental and health factors. The use of EnV-S is illustrated through a case study comparing systems that abate emissions from dielectric chemical vapor deposition processes.     

Protection of semiconductor devices, circuits, and equipment from voltage transients

In this paper a survey is presented of the means that can be applied to the suppression of voltage transients that can affect the reliability of equipment and systems employing semiconductor devices. Consideration is given to some of the ways transients are generated, their duration and magnitudes, and the approach taken in the military standard MIL-STD-704 in confining the power supply characteristics within definite limits which must be tolerated by the utilization equipment. Emphasis is placed on the various techniques--their advantages and limitations--that can be applied in suppressing transients generated from 28-volt dc power supplies. In addition, various device approaches used to limit voltage transients to rectifier diodes are also presented.     

Use of high temperature operating life data to mitigate risks in long-duration space applications that deploy commercial-grade plastic encapsulated semiconductor devices

Commercial-grade plastic encapsulated semiconductor devices are now widely used in space and military equipment for their cost-per-performance and availability advantages over military type ceramic parts. However, many equipment manufacturers still perceive risks in their deployment, and conduct expensive and time-consuming screening and qualification programs to mitigate the potential risks associated with their use.This paper discusses the limitations of the screening and qualification approach currently employed by space equipment manufacturers to assess the long-term reliability of commercially-available plastic encapsulated semiconductor devices (PEDs) in deep space missions. In addition, the paper presents the value of the high temperature operating life (HTOL) data published by manufacturers of PEDs for mitigating the risks associated with the use of such devices in long-duration space applications, where steady-state temperature is the significant stress parameter.     

半导体设备市场的新动向

由于全球半导体市场温和增长和全球半导体资本支出市场从不缓至下滑,导致全球半导体设备市场增长放缓,2007年增长3%～4%,2008年可能出现下滑,中国台湾地区已成为全球第二大半导体设备、材料市场。光刻设备市场看好,2006～2012年复合年增长率将达到13%。450mm晶圆是半导体产业发展的必然趋势,向450mm晶圆过渡的最佳时间是2013年前后。     

Enhancement of semiconductor equipment communications using aweb-enabled equipment driver

Equipment communications are essential for semiconductor manufacturing automation. Equipment managers generally function to communicate between the manufacturing execution system (MES) and equipment. Connecting a different machine to the equipment manager requires modifying the associated equipment driver (ED) accordingly, which needs some efforts. To solve this problem, this study proposes a novel, web-enabled equipment driver (WED) that uses mobile object technology. Initially, a mobile object model with a Java applet, namely WED, is developed. WED is constructed on the equipment (server) side. Then, the equipment manager (client) downloads WED via a web browser. This process does not need to modify ED. Subsequently, the equipment manager can communicate with the equipment by either the Java socket technology using the high-speed SECS message services (HSMS) standard or the object web technology through the common object request broker architecture (CORBA) or distributed component object model (DCOM) protocols using the object-based equipment model (OBEM) standard. This proposed scheme has been successfully implemented. Illustrative examples reveal that the proposed mobile object model and WED establish a novel, efficient, and versatile scheme for semiconductor equipment communications     

2005/2010年的全球半导体

讨论了2005/2010年的全球半导体市场、半导体工艺、半导体设备和中国半导体产业。同时, 还介绍了ITRS2001、摩尔定律对2005/2010年全球半导体的预测。     

Systems of multiple cluster tools: configuration, reliability, and performance

The migration of semiconductor processes to single-wafer vacuum cluster tools has rendered configuration an important decision variable in fab operation and heightened the impact of reliability on fab performance. We address these closely linked issues by deriving the optimal configuration and operation of systems of cluster tools in the presence of scheduled maintenance. The two extremes in the spectrum of possible configurations are the serial configuration, in which the modules in a tool are all different, each representing a step in a process sequence, and the parallel configuration, in which each tool is assigned only one process step. We predict that the latter can offer higher throughputs. However, this advantage may be slight when equipment downtime is relatively schedulable and infrequent, in which the case the serial configuration may be preferable because of its superior cycle times. We also derive optimal lot sizing and release policies for systems of cluster tools. We conclude that fabs will gradually migrate from parallel configurations to serial as cluster tools become more reliable and cycle time becomes more important.     

Organic outgassing behavior of plastic material and reduction of organic contamination in semiconductor equipment

We developed a low organic contamination (LOC ) electric cable as part of efforts to reduce organic contamination in semiconductor equipment. Our development strategies for LOC cables were obtained from the study of the behavior of outgassing from electric cables and the behavior of adsorption on silicon wafers. Strategy I: Reduce low boiling point organic contaminants from electric cables. Strategy II: Reduce organic contaminants with high adsorption rates on silicon wafers. Developing LOC cable under these two strategies, consequently, the amount of organic contaminants that are outgassed from the developed LOC cable was 1/10 or less of the level that is achieved by conventional cables. When compared with conventional cables, the flame-retardancy and flexibility are comparable. Then, we installed LOC cables in actual semiconductor equipment. The amount of organic contaminants adsorbed on the silicon wafer exposed in the equipment that was installed LOC cable and other low outgas parts were 1/6 lower than the conventional equipment. By using this low-outgassing cable in semiconductor equipment, we succeeded in reducing organic contamination in the equipment.     

A Novel Virtual Metrology Scheme for Predicting CVD Thickness in Semiconductor Manufacturing

In an advanced semiconductor fab, online quality monitoring of wafers is required for maintaining high stability and yield of production equipment. The current practice of only measuring monitor wafers may not be able to timely detect the equipment-performance drift happening in-between the scheduled measurements. This may cause defects of production wafers and, thereby, raise the production cost. In this paper, a novel virtual metrology scheme (VMS) is proposed for overcoming this problem. The proposed VMS is capable of predicting the quality of each production wafer using parameters data from production equipment. Consequently, equipment-performance drift can be detected promptly. A radial basis function neural network is adopted to construct the virtual metrology model. Also, a model parameter coordinator is developed to effectively increase the prediction accuracy of the VMS. The chemical vapor deposition (CVD) process in semiconductor manufacturing is used to test and verify the effectiveness of the proposed VMS. Test results show that the proposed VMS demonstrates several advantages over the one based on back-propagation neural network and can achieve high prediction accuracy with mean absolute percentage error being 0.34% and maximum error being 1.15%. The proposed VMS is simple yet effective, and can be practically applied to construct the prediction models of semiconductor CVD processes.     

光学光刻设备发展和展望

在半导体技术和制造的发展中,半导体加工技术中最为关键的光刻技术和光刻工艺设备,必将发生显著的变化,本文将对光刻技术和光刻设备的发展历史进行简述,并展望未来光刻技术的趋势.     

Auto-calibrated potential map drawing equipment and its application to characterization of plasma-coupled devices

By utilizing the voltage contrast mode observed in a scanning electron microscope, the authors have fabricated equipment which they call auto-calibrated potential map drawing equipment (AP-MADE). This equipment can be used to observe the two-dimensional potential distribution on a semiconductor device surface and to draw its equipotential curves. Therefore, it can be used as a semiconductor device analyzer. Utilizing the APMADE, the transfer characteristics of plasma-coupled devices are analyzed in detail and its best asymmetric structure is pointed out quantitatively.