4M Knowledge base - papers
A new tool for aligned micro-embossing and nano-imprinting
T.Rogers & I.Malmros
Applied Microengineering Limited, Unit 8 Library Avenue, Didcot, Oxon.,OX11 0SG, UK
Abstract
A new multi-purpose MEMS fabrication tool is described. The tool enables in-situ aligned embossing and nanoimprinting, in addition to surface activation and aligned wafer bonding. De-embossing is also included in-situ via the use of vacuum chucks and chamber pressurisation. The multi-purpose tool enables the fabrication of bonded, embossed, multi-layer, micro-fluidic devices, for example PDMS structures on silicon, including the alignment of the embossed structure to any pre-existing patterning on the silicon. Examples are presented of various structures that have been made using the tool along with a description of the principles of operation.
categories
hot embossing | Hot/UV embossing | MEMS | Nanoimprint lithography (NIL) | surface activation | wafer bonding
| 69 reads | Fabrication of piezoelectric thick-film bimorph micro-actuators from bulk ceramics using batch-scale methods
R.P.Jourdain and S.A.Wilson
Materials Department, School of Applied Sciences, Cranfield University, Cranfield, Bedfordshire, MK43 0AL, United Kingdom
Abstract
Piezoelectric ceramic films in the 20-60 micron thickness range are rarely employed today in commercial micro-mechanical devices, even though their expected force capability suggests that they are well suited to many micro-fluidic and micro-pneumatic applications. Some examples would be micro-scale fuel cells and micro-combustors. Head sliders, radio-frequency (RF) micro-switches and powered micro-optics are further potential application areas. These are only a few and the barriers in bringing them into reality are those of processing compatibility rather than commercial desirability. Such issues are being addressed in the EU Framework 6 Project ‘Q2M’, which focuses on batch-scale fabrication issues for high quality new micromechanical devices that are cost-effective and which have extended capabilities.
This paper discusses a potential batch-scale production route for piezoelectric thick-film bimorph microactuators that combines ultra-precision grinding of ceramics and femto-second laser machining, along with standard micro-fabrication techniques such as wafer bonding. This new method has the key advantage that many different shapes and thicknesses of actuator can be made with only minor process changes, meaning that actuators can be designed to suit their intended application. It contrasts with current practice whereby micro-actuators are often designed around a limited range of standard components, with consequent reduction in their achievable performance. The examples used are a 6mm diameter plane-spiral bimorph actuator for integration into a polymeric micro-valve and 2-5mm long bimorph cantilevers intended for use in
a new type of silicon ‘house’ micro-valve, with pneumatic applications.
categories
actuators | Bimorph | ceramic based | femto-second | Mechanical machining | MEMS | micro-actuator | PZT | ultra-precision grinding | wafer bondingThe integration of mono-crystalline silicon micro-mirrors on CMOS for SLM applications
F. Zimmera, M. Friedrichsa, M. Lapisac, F. Niklausc, M. Muellera, T. Bakkeb, H. Schenka, H. Laknera
a Fraunhofer Institute for Photonic Microsystems (IPMS), Maria-Reiche-Str. 2, D-01109 Dresden, Germany
b SINTEF Department of Mikrosystems and Nanotechnology, Gaustadalleen 23C, Oslo, Norway
c KTH, The Royal Institute of Technology, Stockholm, Sweden
Abstract
Spatial light modulators (SLMs) based on micro-mirrors for use in DUV lithography and adaptive optics need very high mirror planarity as well as mirror stability. We will present results of new micro-mirror arrays, consisting of monocrystalline silicon, which is a material to fulfil these requirements. As all mirrors of the SLM can be separately activated by an underlying CMOS circuit, the integration of CMOS and MEMS must be achieved, which results in certain restrictions on processing temperatures and the compatibility of materials. Therefore a special low temperature bonding technology has been developed, using an adhesive polymer. This technique provides the transfer of a 300nm thin mono-crystalline silicon layer to the CMOS wafer using only 250°C. First silicon micro-mirrors have been made and characterized using pure adhesive polymer (PMGI), improvements using a mix of an inorganic material with a thin bond-polymer benzocyclobutene BCB) on top are in development. Both approaches and their results will be discussed and presented in detail.
categories
Assembly & packaging | Lithography | maskless lithography | micro-mirrors | Optical MEMS | spatial light modulator | wafer bonding
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