Design and fabrication of a novel thermally actuated vertical bimorph scanner for an integrated AFM

This paper presents the concept and design of a new lateral scanning system for an integrated atomic force microscope (AFM). The core part of the scanner is formed by vertical bimorph beams, which are reported for the first time in this paper. They consist of silicon beams side-coated with aluminium, which bend upon heating causing movement in the horizontal plane. Combining vertical bimorphs with planar bimorphs allows three-dimensional actuation. Theoretical analyses comprising electro-thermal and thermo-eleastic calculations show that large actuation movements are possible at low electrical input power and low input voltage. A process has been developed to deposit aluminium onto sidewalls of silicon beams. Furthermore, the fabrication process for the actuator is described.