Enhancement of microcantilever beams fabrication and determination of their mechanical properties using nanoindentation

Abstract

Microcantilever beams were fabricated through a microelectromechanical system fabrication process; this process was improved by using etched slots. The actual mechanical properties of the cantilever beams can be estimated using a nanoindenter. Various cantilever beam widths and length-to-width ratios were used for evaluation. Five structures of cantilever beams were fabricated and compared. ANSYS software was used to simulate cantilever beam deflections. The etched slots increased the cantilever beam deflections, and the increase in deflection was apparent when the etched slot was located near the base of the beams. Type 4 was a cantilever beam with an etched slot of length L/2 near the base of the beam. The area of the etched slots of type 4 was larger, and the etched slot of type 4 was near the base of the cantilever beam. Type 4 had the shortest etching time, highest fabrication success rate, and greatest deflection. The difference between the measured and simulated (without parameter modification) deflections could exceed 10%. Modifying the force acting point and Young's modulus in the simulations reduced the difference between the measured and simulated deflections to 0.5%. This demonstrates that actual experimental conditions considerably influence simulation results, and this can be beneficial to subsequent studies.