We propose an integration method of heterogeneous micro-electro-mechanical-system (MEMS) structures by liftoff and stamping transfer using a poly-dimethylsiloxane (PDMS) sheet. Silicon structures fabricated on multiple wafers were lifted off by PDMS sheets, and integrated onto a single wafer by the stamping transfer method with a high yield (> 90 %) and high accuracy (position error < 500 nm). A three-dimensional assembly of pyramid-like and inverted pyramid-like structures was demonstrated by our method. This demonstrates that our method will enable us to integrate process-incompatible heterogeneous MEMS structures onto a single wafer.

References :
Hiroaki Onoe, Eiji Iwase, Kiyoshi Matsumoto, Isao Shimoyama, “3D Integration of Heterogeneous MEMS Structures by Stampig Transfer,” The 20th IEEE International Conference on Micro Electro Mechanical Systems (MEMS '07), pp. 175-178, Kobe, Japan, January 21-25, 2007. [Proceedings]

Hiroaki Onoe, Eiji Iwase, Kiyoshi Matsumoto, Isao Shimoyama, “Three-Dimensional Integration of Heterogeneous Silicon Micro-Structures by Liftoff and Stamping transfer,” Journal of Micromechanics and Microengineering, vol. 17, no. 9, pp. 1818-1827, 2007. [Paper]