Improved dicing method for the microflown particle velocity sensor

We report on progress in the fabrication of the microflown particle velocity sensor. The microflown is an acoustic sensor which measures the particle velocity part of sound, contrary to conventional microphones that measure acoustic pressure. It consists of three silicon nitride beams (1500μm x 2μm x 0.18μm) with a platinum layer on top. The last process of the fabrication involves protecting the wires with photo resist followed by dicing. We present a new fabrication method where the devices are diced before releasing the wires thus drastically decreasing the chance of damaging the beams. Preliminary results show a yield of 89%.