Thilo Schmidt

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.

Process development support environment: a tool suite to engineer manufacturing sequences

This paper investigates the practices for developing manufacturing processes in the high tech industries and specifically in the field of MEMS based on semiconductor thin film process technologies. For this purpose the current development practices are described, issues arising from the current practices are extracted and ways to approach these issues are highlighted. Solutions to several of these problems are provided by a software tool suite called XperiDesk. This suite results from a three year project funded by the European Commission under the 6th framework programme. The project called PROMENADE European Commission resulted in prototype software tools which are currently in a maturity phase and will be released as XperiDesk product suite.

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.

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.

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”.

Comprehensive design and process flow configuration for micro and nano tech devices

The development of micro and nano tech devices based on semiconductor manufacturing processes comprises the structural design as well as the definition of the manufacturing process flow. The approach is characterized by application specific fabrication flows, i.e. fabrication processes (built up by a large variety of process steps and materials) depending on the later product. Technology constraints have a great impact on the device design and vice-versa. In this paper we introduce a comprehensive methodology and based on that an environment for customer-oriented product engineering of MEMS products. The development is currently carried out in an international multi-site research project.

Verification of thin film processes in a virtual fabrication environment

Thin film fabrication processes for MEMS are characterized by a variety of different process technologies and materials. Unlike in microelectronics the MEMS fabrication process is in most cases application specific and therefore integral part of the application design. Discovering the correct combination of process steps, materials and process parameters usually requires many expensive and time consuming experiments. This paper presents a new software system that supports the MEMS device and process designers in managing their process knowledge and in verifying their fabrication processes in virtual fabrication environment, thus reducing the number of real world experiments to a minimum.

Management and verification for MEMS fabrication processes

In MEMS design many different fabrication techniques and materials are involved and the strong dependency between microstructure and fabrication process leads to application specific fabrication processes. A comprehensive management of process knowledge is required to take into account the various interdependencies and constraints occurring within a MEMS fabrication process. This paper presents an environment for the management of process knowledge and provides support for the design and verification of application specific fabrication processes.