Piezo-thermal Probe Array for High Throughput Applications

Sens Actuators A Phys. 2012 Oct 1:186:125-129. doi: 10.1016/j.sna.2012.03.033.

Abstract

Microcantilevers are used in a number of applications including atomic-force microscopy (AFM). In this work, deflection-sensing elements along with heating elements are integrated onto micromachined cantilever arrays to increase sensitivity, and reduce complexity and cost. An array of probes with 5-10 nm gold ultrathin film sensors on silicon substrates for high throughput scanning probe microscopy is developed. The deflection sensitivity is 0.2 ppm/nm. Plots of the change in resistance of the sensing element with displacement are used to calibrate the probes and determine probe contact with the substrate. Topographical scans demonstrate high throughput and nanometer resolution. The heating elements are calibrated and the thermal coefficient of resistance (TCR) is 655 ppm/K. The melting temperature of a material is measured by locally heating the material with the heating element of the cantilever while monitoring the bending with the deflection sensing element. The melting point value measured with this method is in close agreement with the reported value in literature.

Keywords: Elastography; High throughput; Mechanical characterization; Melting point; Microcantilevers; Parallel imaging; Piezoresistive sensing; Scanning probe microscopy.