The MMST computer-integrated manufacturing system framework

Computer-integrated manufacturing (CIM) is the harmonious connection, integration, and interoperation of automation equipment within a manufacturing facility. In a semiconductor wafer fab, this includes integration of the processing equipment with all of the supporting systems for product and process specification, production planning and scheduling, and material handling and tracking. Traditionally, CIM systems have been characterized as monolithic mainframe-based systems and/or inflexible islands of automation with limited interoperability. Today's manufacturing demands fully integrated dynamic systems which directly support the concepts of lean, flexible and agile manufacturing to high quality standards. These requirements drove the design of a new CIM system which was developed for the Microelectronics Manufacturing Science and Technology (MMST) program. This paper provides an overview of the MMST CIM system framework which is based on open distributed system and object technologies. The CIM system was demonstrated in a 1000 wafer pilot production run in 1993 which achieved world record cycle time, and is now being commercialized as part of the WORKS product family from Texas Instruments     

New tools for yield improvement in integrated circuit manufacturing: can they be applied to reliability?

This paper will start with a discussion of why probe yield (the number of good chips per silicon wafer) is so important to financial success in integrated circuit manufacturing. Actual data will be quoted and a numerical example shown. A simple model will be given to demonstrate the main factors influencing yield and the relationship between yield and reliability of the final product. In the last few years a range of new tools have been deployed in manufacturing, and these have accelerated the pace of yield improvement, thus increasing competitive pressures. These tools will be described, along with examples of their use. Topics will include in-line inspection and control, automatic defect classification and data mining techniques. A proposal is made to extend these tools to the improvement of reliability of products already in manufacturing by maintaining absolute chip identity throughout the entire wafer fabrication, packaging and final testing steps.     

Quick-turnaround-time improvement for product development andtransfer to mass production

We describe equipment and facility operational methods in a production fab which are designed to achieve quick-turnaround-time (QTAT) manufacturing and ease product transfer from development to mass production. An advanced CIM system with precise lot management is introduced to keep the optimum balance of manufacturing TAT and throughput. Substantial end-user computing reduces the engineering holding time for handling development lots. In situ monitoring technologies are applied for the utilization enhancement of plasma-assisted equipment. A 9% manufacturing TAT reduction and a 14% throughput increase are estimated using a manufacturing simulator. The number of wafers in QTAT lots is reduced for processing time reduction. As a result, manufacturing TAT of QTAT lots with reduction from 24 wafers to three is reduced to 56% compared with that of normal lots in the production fab. This new production fab realizes QTAT development and agile product transfer from development to mass production with full process compatibility     

Polysilicon RTCVD process optimization forenvironmentally-conscious manufacturing

In the semiconductor manufacturing industry, optimization of advanced equipment and process designs must include both manufacturing metrics (such as cycle time, consumables cost, and product quality) and environmental consequences (such as reactant utilization and by-product emission). We have investigated the optimization of rapid thermal chemical vapor deposition (RTCVD) of polysilicon from SiH₄ as a function of process parameters using a physically-based dynamic simulation approach. The simulator captures essential time-dependent behaviors of gas flow, heat transfer, reaction chemistry, and sensor and control systems, and is validated by our experimental data. Significant improvements in SiH₄ utilization (up to 7×) and process cycle time (up to 3×) can be achieved by changes in 1) timing for initiating wafer heating relative to starting process gas flow; 2) process temperature (650-750°C); and 3) gas flow rate (100-1000 seem). Enhanced gas utilization efficiency and reduced process cycle time provide benefits for both environmental considerations and manufacturing productivity (throughput). Dynamic simulation proves to be a versatile and powerful technique for identifying optimal process parameters and for assessing tradeoffs between various manufacturing and environmental metrics     

LTCC package for high temperature applications

There is a growing demand for sensors and electronics that can work in harsh environments and at high temperature. Applications include sensors and actuators for control in petroleum and geothermal industry, process monitoring and distributed control systems in the automotive and aerospace fields. Process development and packaging materials for electronic devices are closely connected to such packaging issues. In many cases the package is as important as the device itself in meeting the applications needs.Low temperature co-fired ceramics (LTCC) and thick-film technologies have the potential to incorporate multilayer structures, enabling fabrication of specialized packaging systems. LTCC technology enables easy electrical or optical connections within and between layers in addition to enabling use of integrated passive components, heaters, sensors, converters etc.This paper presents attempts to develop a reliable packaging technology for silicon carbide (SiC) based hydrogen sensors operating at temperatures up to 300 °C. Some simulations of thermal properties were carried out and package structures were made and investigated. The package protects the sensor against mechanical damage and makes possible easy electrical connections. Moreover, the heater and temperature sensors allow for proper temperature regulation of the element. The manufacturing process, basic electrical parameters of the integrated heater as well as real temperature distribution are presented.     

器件变更管理

上游厂家的器件变更、停产是研发制造型企业产品设计、生产和维护中经常碰到的问题。该文介绍了器件变更及停产通知,讨论了器件变更的实施途径,这些管理和控制,对于延续产品的质量和可靠性至关重要,尤其是批量生产的产品。     

The effect of dynamic design processing for yield enhancement inthe fabrication of deep sub-micron MOSFET's

With the downscaling of microelectronic devices, tighter process control and more elaborate fabrication equipment need to be complemented by process correcting techniques if good quality and high yields are to be expected. Dynamic design processing-a forward correcting technique by which some recipe values are recalculated during manufacturing-is such a technique. In this paper the effect of dynamic design processing on deep sub-micron MOSFET's is presented. The results show that a parametric yield improvement in excess of 25% over conventional manufacturing can be achieved     

Fault diagnosis and computer integrated manufacturing systems

This paper examines one aspect of human interaction with computer-integrated systems, that of fault diagnosis or troubleshooting. The complexity (and attendant unreliability) of the new manufacturing systems has meant that fault diagnosis has become an increasing proportion and an integral part of operators' jobs. Establishing and maintaining high levels of diagnostic accuracy and efficiency is important for a variety of reasons. One is that equipment downtime is expensive, another is that errors of diagnosis might, under some circumstances, be a threat to both safety and quality. As yet there has been little research into human fault diagnosis in CIM. This paper draws on research from other industries, such as power generation and chemical production and explores the application of that work to fault-finding in computer-integrated discrete production systems. The focus is on the factors that influence individual fault-finding behaviors and efficiencies. Where possible, the aim is to identify critical human-machine interaction design principles and to highlight research questions yet to be addressed in contemporary manufacturing environments, with respect to the diagnosis of system failures     

Requirements of CAM in IC technology

Ultra clean technology (ultra clean processing environment, ultra clean wafer surface, perfect process-parameter control) is a crucial factor in developing high quality process technology for future ULSI fabrication. Wafers should never be exposed to air. The possibility of performing all wafer processes in equipment having the same hardware configuration is discussed based on the concept of a closed manufacturing system in conjunction with highly advanced super clean systems.     

MMST manufacturing technology-hardware, sensors, and processes

This paper describes the equipment and processes utilized in the Microelectronics Manufacturing Science and Technology (MMST) program. The processes were carried out in a combination of testbeds (AVP, the TI designed and built Advanced Vacuum Processor) and commercial equipment, all in the single-wafer mode. All AVP processing was performed with the wafers in an inverted, face-down, configuration. All the processing equipment was connected to a Computer-Integrated Manufacturing (CIM) system, which both collected the designated data and communicated the process parameters from the CIM database to the particular processing unit. Where available, in situ sensors were utilized for monitoring the process parameters, with measurements made on a metrology die in the center of the wafer. Many of these processes were controlled by the model-based process control algorithms in the CIM system. Otherwise, the processes were controlled by standard statistical process control (SPC) methods. This paper emphasizes the processing methodology that was developed and followed in order to operate in this CIM environment and successfully execute an approximately 150 step 0.35 μm CMOS process in less than 72 hours     

Benchmarking semiconductor manufacturing

We are studying the manufacturing performance of semiconductor wafer fabrication plants in the US, Asia, and Europe. There are great similarities in production equipment, manufacturing processes, and products produced at these plants. Nevertheless, data reported here show that important quantitative measures of productivity vary by factors of 3 to as much as 5 across an international sample of 16 plants. We conducted on-site interviews with manufacturing personnel to better understand reasons for the observed wide variations in productivity. We have identified factors in the areas of information systems, organizational practices, process and technology improvements, and production control that correlate strongly with productivity     

印制板企业精益生产之条码管理方法探讨

印制板企业因为工艺流程长、质量要求高、制造柔性高等众多因素,对订单管理带来了挑战。一批小批量印制板制造企业在接单、制造、仓储等各个环节,庞大的订单、工单、物流数据管理一直是公司业务管理的难点和重点。在此,通过分析引进ORCLE ERP系统,采用订单、工单合一的全流程条码管理,追踪产品流动的全过程,较好的解决了小批量线路板企业产品物流管理难题。     

装片机漏晶检测器的改造——reflection反射功能

随着市场经济竞争激烈,提高产品质量及合格率、降低成本是企业关注的核心问题。IC封装过程中的来料数和实际装片数之差即CV,这个数字客户一般仅给0.5%的控制。正常情况下,只要我们设备、检测系统没有问题,这个数值应该可以保证。但实际操作过程中,会发生或短缺很多(需要赔偿客户),或废品很多(影响封回率),影响这一数值的关键部位就是———漏晶检测系统。     

Managing technology CAD for competitive advantage: an efficientapproach for integrated circuit fabrication technology development

This paper describes a methodology to exploit the full capabilities of technology computer-aided design (TCAD) for the development of integrated circuit fabrication processes. The development process of integrated circuits is represented by a simple model that describes the technology specifications at the beginning and the product specifications at the end of the product development cycle. Considering this model, different intermediate tasks are defined to obtain initial guess process recipe from the target product specifications. The complete technology development is shown to be achieved using TCAD in three different phases such as the generation of initial guess process recipe, the optimization of process technology, and the evaluation of process manufacturability. A simple quantitative analysis to estimate the major advantages of TCAD in reducing the cycle time and cost of technology development is presented. The technical limitations of TCAD and the measures to address these limitations are discussed. The organizational and social issues of the implementation of TCAD and the managerial responsibilities in adopting TCAD for the development of integrated-circuit fabrication process are also discussed     

Development of a virtual metrology for high-mix TFT-LCD manufacturing processes

Nowadays,TFT-LCD manufacturing has become a very complex process,in which many different products being manufactured with many different tools.The ability to predict the quality of product in such a high-mix system is critical to developing and maintaining a high yield.In this paper,a statistical method is proposed for building a virtual metrology model from a number of products using a high-mix manufacturing process.Stepwise regression is used to select key variables that really affect the quality of th...     

Analysis of mixed-signal manufacturability with statisticaltechnology CAD (TCAD)

We have developed a methodology which combines technology CAD (TCAD) simulation with statistical analysis of empirical data to predict and control the manufacturability of IC fabrication processes. As a result, manufacturing tolerance or sigma-based models (also known as worst-case models) can be determined before a significant sample size of fabricated devices can be characterized. Early on in the development cycle, empirical data is collected, and models built from simulated data are refined. These revised models are used to determine process control limits, and optimize in-line and electrical test measurement (E-test) for maximum observability of variation. As the process is stabilized, further refined models are used to perform yield diagnosis and tolerance analysis of circuits. This methodology has been applied to a number of BJT and submicrometer CMOS processes to create predictive sigma-based models, modify the fabrication recipe to meet objective specifications as development proceeds, and finally use them to control the manufacturing line     

MAP/TOP in CIM distributed computing

The distributed computing communication needs of computer-integrated manufacturing (CIM) are discussed. The capabilities of MAP/TOP (manufacturing automation protocol/technical and office protocol) as a communications architecture are examined. An example of how MAP/TOP operates in a hypothetical CIM enterprise is presented     

从用户角度看芯片贴装头技术

现代制造商一直特别看重在变动过程中迅速重新配置平台型贴装机的灵活性,以便能够对变动后的产品实现最优的贴装能力.现在,平台型贴装设备上提供的新一代贴装头技术扩展了这些系统的能力,可以提供高速芯片贴装功能,实现能够在不需重新配置,不会影响精度、良品率或产能的情况下,贴装常用的各种元件.它能使未来几代装配商将从更加灵活、自适应和精确的贴装头中受益,他们将提高利用率,大大降低变动时间,明显减少支持高速度、低成本、快速交货周期制造环境所需的反应时间.