Remote power feed and control of MEMS with 58 V silicon photovoltaic cell made by a CMOS post-process dry release and device isolation method

A small autonomous device integrating MEMS, CMOS and photovoltaic (PV) cells has many attractive applications. For such a device, using light as a power source is preferable because power feeding and control signal transmitting can be done at the same time and in a remote manner. We demonstrated the remote power feeding to a MEMS actuator by light using PV cell array. In this article, we first proposed a new dry release method of MEMS structure for a CMOS-MEMS-PV integration. The method does not require vapor HF and thus we can avoid damage to CMOS circuits. We demonstrated the method by releasing MEMS cantilevers. Next, we prepared a PV cell array integrable with CMOS and MEMS. Its open circuit voltage was 58 V and its maximum power was 43.3 μW. We conducted an experiment to drive a MEMS comb drive actuator remotely, irradiating laser light from the distance of 1.5 m. The PV cell array successfully fed power and the actuator moved 1.0 μm, two-thirds of the calculated value.