Fabrication of large-scale mono-crystalline silicon micro-mirror arrays using adhesive wafer transfer bonding
2009 (English)In: Proceedings of SPIE - The International Society for Optical Engineering / [ed] David L. Dickensheets, Harald Schenk, Wibool Piyawattanametha, 2009, Vol. 7208, 720807- p.Conference paper (Refereed)
Today,spatial light modulators (SLMs) based on individually addressable micro-mirrors playan important role for use in DUV lithography and adaptiveoptics. Especially the mirror planarity and stability are important issuesfor these applications. Mono-crystalline silicon as mirror material offers agreat possibility to combine the perfect surface with the goodmechanical properties of the crystalline material. Nevertheless, the challenge isthe integration of mono-crystalline silicon in a CMOS process withlow temperature budget (below 450°C) and restricted material options. Thus,standard processes like epitaxial growth or re-crystallization of poly-silicon cannotbe used. We will present a CMOS-compatible approach, using adhesivewafer transfer bonding with Benzocyclobutene (BCB) of a 300nm thinsilicon membrane, located on a SOI-donor wafer. After the bondprocess, the SOI-donor wafer is grinded and spin etched toremove the handle silicon and the buried oxide layer, whichresults in a transfer of the mono-crystalline silicon membrane tothe CMOS wafer. This technology is fully compatible for integrationin a CMOS process, in order to fabricate SLMs, consistingof one million individually addressable mono-crystalline silicon micro-mirrors. The mirrors,presented here, have a size of 16×16 µm2. Deflection isachieved by applying a voltage between the mirrors and theunderlying electrodes of the CMOS electronics. In this paper, wewill present the fabrication process as well as first investigationsof the mirror properties.
Place, publisher, year, edition, pages
2009. Vol. 7208, 720807- p.
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-25362DOI: 10.1117/12.808694ISI: 000285753800006ScopusID: 2-s2.0-67649183018OAI: oai:DiVA.org:kth-25362DiVA: diva2:358556
MOEMS and Miniaturized Systems VIII,San Jose, CA, USA , 27 January, 2009
QC 201010222010-10-222010-10-192011-11-22Bibliographically approved