Abstract
High frequency bending mode membranes are fabricated using a 1μm PZT thick film deposited by sol-gel. Finite Element Analysis (FEA) is used to tailor the membrane radius to a resonant frequency in the 5-10MHz frequency range. Using a radius of 16 and 24μm, devices are produced as individual cells as well as 3x3 and 5x5 arrays. The arrays are designed so that the bottom electrode is common to all cells whereas the top electrode is only common to a column of 5 or 3 cells depending on the type of arrays. Within a column each cell was separated by a wall of silicon (having the length of the substrate of silicon) in order to sustain the array, reduce parasitic vibrations, hence cross-talk. A 16μm radius membrane shows a resonant frequency of 9MHz and a coupling coefficient of 11%. Suspended cells are also investigated to increase frequency further. Two arms-suspended cells resonate at 8.1MHz for a 24μm radius membrane. © 2006 IEEE.