Bücher

Optical Methods for the Inspection of Microsystems

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
The miniaturization of complex devices such as sensors and actuators is one of the biggest challenges in modern technology. Different manufacturing technologies, for example the LIGA-technique and UV-lithography, allow the realization of non-silicon and silicon micro parts with a high aspect ratio and structural dimensions in the range from nm to mm. LIGA is an acronym that stands for the main steps of the process, i.e., deep X-ray lithography, electroforming, and plastic molding. These three steps make it possible to mass-produce high quality micro components and micro structured parts, in particular from plastics but also from ceramics and metals, at low-costs. Techniques based on UV-lithography or ASE (Advanced Silicon Etching) processes allow for the direct integration of the electronics to realize advanced MEMS (Micro-ElectroMechanical Systems) devices. Further technologies such as laser micro-machining, electro-chemical milling (ECM), electro-discharge machining and nanoimprint lithography (NIL) offer meanwhile an economical, high resolution alternative to UV and VUV for the next-gen eration optical lithography. Increased production output, high system performance, product reliability and improved lifetime are important conditions for trust in a new technology and are deciding factors for its commercial success. Consequently, high quality standards are a must for all manufacturers. However, with increasing miniaturization the importance of measurement and testing is rapidly growing and therefore the need in microsystems technology for suitable measurement and testing procedures is evident. Both, reliability and lifetime are strongly dependent on the material properties and the thermo-mechanical design. In comparison to conventional technologies the situation in microsystems technology is extremely complicated. Modern microsystems (MEMS and MOEMS) and their components are characterized by high volume integration of a variety of materials and materials combinations. This variety is needed to realize the very different and variable functions such as sensor and actuator performance, signal processing, etc. But it is well known that the material behavior of a new structural design cannot be easily predicted by theoretical simulations. A possible reason for the incorrect predictions made by FEM calculations for the operational behavior of microdevices is the lack of reliable material data and boundary conditions in the micro scale. Therefore, measurement and testing procedures are confronted with a complex set of demands. In general, the potential of the following is challenged:
 
• microscopic and nanoscopic measurement and testing at the wafer scale,
• fast in-line measurement of various dimensional and functional properties of highly heterogeneous hybrid systems,
• verification of system specifications including geometrical, kinematical and thermo-mechanical parameters,
• fast and reliable recognition of surface and sub-surface defects allowing the possibility of further review and repair,
• measurement of complex 3D-structures with a high aspect ratio and
• determination of material properties which are well defined for the bulk material but are still to be specified for the micro scale
 
Measurement and inspection techniques are required are that are very fast, robust, and relatively low cost compared to the products being investigated. The reason for this demand is obvious: the properties determined on much larger specimens cannot be scaled down from the bulk material without experimental verification. Further in the micro scale the material behavior is noticeably affected by the production technology. Therefore simple and robust methods to analyze the shape and deformation of the microcomponents are needed. Together with the knowledge of the applied load and appropriate physical models this data can be used to derive material parameters and various system properties. However neither a single method nor a class of measurement techniques can fulfill these requirements completely. Conventional tensile testing techniques (e.g. strain gauges) are unable to test specimens over sub-millimeter sized regions because of their limited local resolution and unwanted tactile character. Other approaches, such as, for instance, micro-hardness measurements, do not reveal directional variations. However, full-field optical methods provide a promising alternative to conventional methods. The main advantages of these optical methods are: non-contact, non-destructive and fieldwise working principle, fast response, high sensitivity and accuracy (typical displacement resolution of a few nanometers and strain values of 100 microstrain, high resolution of data points (e.g. 1000x1000 points for a sub-mm field of view), advanced performance of the system i.e. automatic analysis of the results and data preprocessing in order to meet the requirements of the underlying numerical or analytical model. Thus t his book offers a timely review of research in applying optical measurement techniques for microsystems inspection. The authors give a general survey of the most important and challenging optical methods such as light scattering, scanning probe microscopy, confocal microscopy, fringe projection, grid and moiré techniques, interference microscopy, Laser-Doppler-Vibrometry, holography, speckle metrology and spectroscopy. Additionally modern approaches for data acquisition and processing (for instance digital image processing and correlation) are presented.
 
Now availabe here!

Fringe 2005 Proceedings

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
In 1989 the time was hot to create a workshop series dedicated to the dicussion of the latest results in the automatic processing of fringe patterns. This idea was promoted by the insight that automatic and high precision phase measurement techniques will play a key role in all future industrial applications of optical metrology. However, such a workshop must take place in a dynamic environment. Therefore the main topics of the previous events were always adapted to the most interesting subjects of the new period. In 1993 new principles of optical shape measurement, setup calibration, phase unwrapping and nondestructive testing were the focus of discussion, while in 1997 new approaches in multi-sensor metrology, active measurement strategies and hybrid processing technologies played a central role. 2001, the first meeting in the 21st century, was dedicated to optical methods for micromeasurements, hybrid measurement technologies and new sensor solutions for industrial inspection. The fifth workshop takes place in Stuttgart, the capital of the state of Baden-Württemberg and the centre of a region with a long and remarkable tradition in engineering. Thus after Berlin 1989, Bremen 1993, 1997 and 2001, Stuttgart is the third Fringe city where international experts will meet each other to share new ideas and concepts in optical metrology.
 
This volume contains the papers presented during FRINGE 2005. The focus of this meeting was especially directed to resolution enhanced technologies, new approaches in wide scale 4D optical metrology and advanced computer aided measurement techniques. Since optical metrology becomes more and more important for industrial inspection, sophisticated sensor systems and their applications for the solution of challenging measurement problems are chosen again as one of the central topics of the workshop. This extended scope was honored again by a great response on our call for papers. Scientists from all around the world offered more than 110 papers. This enormous response demanded a strong revision of the papers to select the best out of the overwhelming number of excellent papers. This hard job had to be done by the program committee since there is a strong limitation of the number of papers which can be presented and discussed during our workshop without holding parallel sessions.
 
The papers presented in this workshop are summarized under 5 topics:
 
1. New Methods and Tools for Data Processing
2. Resolution Enhanced Technologies
3. Wide Scale 4D Optical Metrology
4. 4. Hybrid Measurement Technologies
5. 5. New Optical Sensors and Measurement Systems
 
Each session is introduced by an acknowledged expert who gives an extensive overview of the topic and a report of the state of the art. The classification of all submitted papers into these topics was again a difficult job which often required compromises. We hope that our decisions will be accepted by the audience. On this occasion we would like to express our deep thanks to the international program committee for helping us to find a good solution in every situation.
 
The editor would like to express his thanks to all the authors who spent a lot of time and effort in the preparation of their papers. Our appreciation also goes to Dr. Eva Hestermann-Beyerle and Monika Lempe from Springer Heidelberg for providing excellent conditions for the publication of these proceedings. My deep thanks is directed to the members of the ITO staff. The continuous help given by Gabriele Grosshans, Ruth Edelmann, Christa Wolf, Reinhard Berger, Witold Gorski, Ulrich Droste, Jochen Kauffmann and Erich Steinbeißer was the basis for making a successful FRINGE 2005. Finally, special thanks and appreciation goes to my co-chair, Werner Jüptner, for sharing with me the spirit of the 5 th Fringe workshop.
 
Looking forward to FRINGE 2009.
 
 
Stuttgart, September 2005
 
Wolfgang Osten
 
 
Now availabe here!

Fringe 2009 Proceedings

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
21 years ago it was a joint idea with Hans Rottenkolber to organize a workshop dedicated to the discussion of the latest results in the automatic processing of fringe patterns. This idea was promoted by the insight that automatic and high precision phase measurement techniques will play a key role in all future industrial and scientific applications of optical metrology. A couple of months later more than 50 specialists from East and West met in East Berlin, the capital of the former GDR, to spend 3 days with the discussion of new principles of fringe processing. In the stimulating atmoshere the idea was born to repeat the workshop and to organize the meeting in an olympic schedule. And thus meanwhile 20 years have been passed and we have today Fringe number six. However, such a workshop takes place in a dynamic environment. Therefore the main topics of the previous events were always adapted to the most interesting subjects of the new period. In 1993 the workshop took place in Bremen and was dedicated to new principles of optical shape measurement, setup calibration, phase unwrapping and nondestructive testing, while in 1997 new approaches in multi-sensor metrology, active measurement strategies and hybrid processing technologies played a central role. 2001, the first meeting in the 21st century, was focused to optical methods for micromeasurements, hybrid measurement technologies and new sensor solutions for industrial inspection. In 2005 the fifth workshop was organized in Stuttgart, the capital of the state of Baden-Würthemberg and the centre of a region with a long and remarkable tradition in machine construction, vehicle manufacturing and optics. Thus after Berlin 1989, Bremen 1993, 1997 and 2001, Stuttgart was the third Fringe city where international experts met each other to share new ideas and concepts in optical metrology. And this will be continued in 2009. This volume contains the papers presented during FRINGE 2009.
The focus of this meeting is especially directed to digital wavefront engineering, resolution enhanced technologies, 4D methods addressing applications from macro to nano considering dynamic changes, sensor fusion and new advances in the unification of modeling, simulation and experiment. Since optical metrology becomes more and more important for industrial inspection, sophisticated sensor systems and their applications for the solution of challenging measurement problems are chosen again as one of the central topics of the workshop. This extended scope was
honored by a great response on our call for papers. Scientists from all X around the world offered more than 150 papers. This enormous response demanded a strong revision of the papers to select the best out of the overwhelming number of excellent papers. The strong limitation of the number of papers which can be presented orally and discussed effectively
during a workshop without holding parallel sessions was again an impotant orientation.
 
The papers presented in this workshop are summarized under 5 topics:
 
1. New Methods and Tools for Data Acquisition and Processing
2. Application Enhanced Technologies
3. 4D Optical Metrology over a Large Scale Range
4. Hybrid Measurement Techniques
5. New Optical Sensors and Measurement Systems
 
As in the former workshops, each topic is introduced by an acknowledged expert who gives an extensive overview and a  report of the state of the art. The classification of all submitted papers into these topics was again a difficult job  which often required compromises. We hope that our decisions will be accepted by the audience. On this occasion we  would like to express our deep thanks to the international program committee for helping us to find a good solution in  every situation.
The editors would like to express their thanks to all the authors who spent a lot of time and effort in the preparation of their papers. Our appreciation also goes to Eva Hestermann-Beyerle and Birgit Kollmar-Thoni from Springer Heidelberg for providing excellent conditions for the publication.
Our deep thanks is directed to the members of the ITO staff. The continuous help given by Katharina Bosse-Mettler, Katja Costantino, Gabriele Grosshans, Heiko Bieger, Valeriano Ferreras Paz, Erich Steinbeißer and Michael Warber was the basis for making a successful FRINGE 2009.
Finally, our special thanks and appreciation goes to all friends and colleagues for sharing with us again the spirit of the Fringe workshops.
 
Looking forward to FRINGE 2013.
 
 
Stuttgart and Warsaw, September 2009
 
Wolfgang Osten and Malgorzata Kujawinska
 
 
Now availabe here!