This 2D motion sensor is Nanusens first product and is being aimed specifically at the earphone market. It is due to sample in 4Q19 and be in volume in 2020.
X-ray of an earbud showing battery and electronics. Source: Nanusens.
Most MEMS sensors use different silicon wafers for the MEMS and signal conditioning ASIC, resulting in a more complex manufacturing process and larger component. Nanusens uses 0.18 micron CMOS processes at SMIC and TSMC and uses a Chinese assembly house, JCAP, part of JCET, to apply vapor etching to release the moving mass, said Josep Montanya, CEO of Nanusens.
The moving mass is created by etching away the intermetal dielectric through openings in the passivation layer using hydrofluoric acid vapor (vHF). The holes are then sealed and the chip packaged as necessary. As standard CMOS processes are used with minimal post-processing the sensors can be directly integrated with active circuitry and the sensors can potentially have high yields similar to CMOS devices.