Kai Hahn

Process management and design for MEMS and microelectronics technologies

Taking into account the tendency towards higher integration based on sophisticated technologies in microelectronics or the use of specific process steps for the realization of MEMS it becomes evident that the impact of properties and parameters from fabrication processes are getting more and more important. For long the interface between the design domain and the process domain was simply expressed in design rules sets. With the use of high resolution and new IC technology steps the interface gets more complex. As far as MEMS are concerned the technology issues are too dominating for fixed interfaces to the design. Novel approaches are necessary to support future design tasks in the area covered by process development on the one hand and application/structure design on the other hand, considering structural design specifications as well as process flow requirements. This paper describes the development of a process design and management environment that supports process engineers and designers to determine valid process step sequences for specific applications and to derive all characterization data from process flows that are relevant for design stages. This environment (acronym PRINCE) is developed in cooperation with a major European MEMS foundry. It is based on a common data base where all process steps and their characterizations as well as derived rules are stored. Users are able to compose process flows on a graphical editor. Consistency violations such as missing or wrong placed process steps within a complete process flow will automatically be detected. Future work will integrate algorithms to optimize process flows.

Computer-aided design tools for economical MEMS fabrication processes

Since the early 70s when microsystem technology was first introduce an enormous market for MST-products has been developed. Airbag sensors, micro pumps, ink jet nozzles etc. and the market is just about to start up. Establishing these products for a reasonable price requires mass production. Meanwhile, also computer-based design-tools have been developed in order to reduce the expenses for MST-design. In contrast to other physical design processes like e.g. in micro electronics, MEMS physical design is characterized by the fact that each product requires a tailored sequence of fabrication steps, usually selected from a variety of processing alternatives. The selection from these alternatives is based on economical constraints. Therefore, the design has a strong influence on the money and time spent to take an MST-product to market.

A knowledge based approach for MEMS fabrication process design automation

In this paper an approach for fabrication process design automation is presented that is backed up by a comprehensive process data management system. The synthesis procedure is roughly based on an approach originally developed at the University of Michigan. It starts with a two-dimensional cross-section representation of the intended MEMS structure that is analysed to identify typical process features. This leads to an abstract process flow frame to be filled with concrete process steps and process sequences from the process data management system.

Optimization of MEMS fabrication process design by virtual experiments

Fabrication processes for MEMS are characterized by a variety of different process technologies and materials. Unlike in microelectronics the fabrication process is relevant to all design stages within the design flow. Discovering the correct combination of process steps, materials and process parameters usually requires a large number of experiments. This paper presents a new software system that supports the MEMS designers in managing their process knowledge and in performing virtual experiments using SILVACO TCAD tools.

MEMS fabrication process management environment

New microfabrication technologies in the MEMS domain require novel approaches in computer aided design. Process issues in these technologies affecting the design are becoming increasingly important and Process information held in static design rule sets will be no longer sufficient. This paper describes the methodology and the implementation of a process management system that supports the designer in configuring application specific process flows with predictable properties.

Software-based development of 3D integration flows

In recent years 3D IC design and manufacturing is continuously emerging. Along with the variety of possibilities on how to vertically integrate two or more dies, many aspects including cost, design and choice of technology must be considered. Therefore a design methodology and software implementation is presented in this paper which makes use of the mutual dependency of design and process technology in order to provide a manufacturable integration flow.

CAD tool environment for MEMS process design support

MEMS fabrication processes are characterized by a numerous useable process steps, materials and effects to fabricate the intended microstructure. Up to now CAD support in this domain concentrates mainly on the structural design (e.g. simulation programs on FEM basis). These tools often assume fixed interfaces to fabrication process like material parameters or design rules. Taking into account that MEMS design requires concurrently structural design (defining the lateral 2-dim shapes) as well as process design (responsible for the third dimension) it turns out that technology interfaces consisting only of sets of static data are no longer sufficient. For successful design flows in these areas it is necessary to incorporate a higher degree of process related data. A broader interface between process configuration on the one side and the application design on the other side seems to be needed. This paper proposes a novel approach. A process management system is introduced. It allows the specification of processes for specific applications. The system is based on a dedicated database environment that is able to store and manage all process related design constraints linked to the fabrication process data itself. The interdependencies between application specific processes and all stages of the design flow will be discussed and the complete software system PRINCE will be introduced meeting the requirements of this new approach. Based on a concurrent design methodology presented in the beginning of this paper, a system is presented that supports application specific process design. The paper will highlight the incorporated tools and the present status of the software system. A complete configuration of an Si-thin film process example will demonstrate the usage of PRINCE.

Web-based learning by engineering for MEMS technologies

The increasing use of Internet-resources worldwide offers new chances in the development of net-based teaching and training materials. Especially in the area of life long learning that is becoming more and more important for persons who are involved in design, production or application of high-tech products in their professional lives, net-based training opens new perspectives. As ordinary classroom courses and centralized training seminars are expensive and draw personnel out of their productive working environments for prohibitively long periods, these traditional training techniques are not well suited to life long learning. This article addresses the results of the TRANSTEC-project. The project addresses this matter by providing a novel concept of interactive Internet-based training entities.

MEMS Product Engineering

This chapter points out the individual challenges of micro electro mechanical system (MEMS) design issues. Starting from device design according to the idea of the product a concurrent technology design (determining the manufacturing flow) is necessary because of the strong dependencies between structural and technological properties. Additionally the challenges of packaging and assembling have to be considered in early design stages. Last but not least the aspect of quality assurance becomes more and more important. Modern strategies like Design for Six Sigma (DfSS) adapted to the MEMS design area can substantially improve the quality and the yield in later production processes.

Sampling process information from unstructured data

Process Data Management and information governance are important tasks in product engineering. Formal process descriptions, quick access to technology data, check for consistent process flows, and the easy reuse of technology data are the main drivers of these developments. This paper introduces new methods for systematically collecting and storing technology data preserving the multidimensional context in which it had been created. Furthermore new methods and tools are introduced reconstructing the context of historical data, therefore creating information from the “heap”.