Thermo-mechanical transduction suitable for high-speed scanning probe imaging and lithography

Abstract

Microelectromechanical systems (MEMS) with integrated read-out and actuation are very useful tools for a wide variation of applications, especially in scanning probe microscopy (SPM) and lithography (SPL). They avoid the use of conventional optical beam deflection techniques or external excitation and are suitable for massively parallel scanning probe solutions and biochemical sensors. Such arrays of beams offer an increased throughput to scan large areas in SPM and SPL. However, the fabrication technology of such complex MEMS requires careful design of all components. This paper presents a comparison between analytical, numerical and experimental data of a cantilever with integrated thermal actuator and piezoresistive sensor, suitable for fast SPM and SPL. The focus of this work lies on the efficiency of the actuator, to achieve a high static displacement, which is required for an array operation. To maximize this displacement, two material compositions for a varying geometry of the beam's layers are analyzed. With a scanning electron microscope and a laser vibrometer an increased displacement of the beam about 10μm can be presented, which is in a good agreement with our theoretical predictions.