Wafer-level integration of NiTi shape memory alloy on silicon using Au-Si eutectic bonding
2013 (English)In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 23, no 1, 1-14 p.Article in journal (Refereed) Published
This paper reports on the wafer level integration of NiTi shape memory alloy (SMA) sheets with silicon substrates through Au-Si eutectic bonding. Different bond parameters, such as Au layer thicknesses and substrate surface treatments were evaluated. The amount of gold in the bond interface is the most important parameter to achieve a high bond yield; the amount can be determined by the barrier layers between the Au and Si or by the amount of Au deposition. Deposition of a gold layer of more than 1 mu m thickness before bonding gives the most promising results. Through patterning of the SMA sheet and by limiting bonding to small areas, stresses created by the thermal mismatch between Si and NiTi are reduced. With a gold layer of 1 mu m thickness and bond areas between 200 x 200 and 800 x 800 mu m(2) a high bond strength and a yield above 90% is demonstrated.
Place, publisher, year, edition, pages
2013. Vol. 23, no 1, 1-14 p.
Microactuators, Gold, Temperature, Fabrication, Film
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-93492DOI: 10.1088/0960-1317/23/1/015008ISI: 000312248200008ScopusID: 2-s2.0-84877969669OAI: oai:DiVA.org:kth-93492DiVA: diva2:516504
FunderEU, European Research Council, 267528
QC 20130110. Updated from accepted to published.2012-04-182012-04-182015-09-30Bibliographically approved