Fabrication and characterization of micro-grating accelerometer

The fabrication and characterization of a micro-grating accelerometer with optoelectronic read out is described. The sensor consists of an Al membrane at the bottom of the bulk silicon proof mass and a rigid Au grating on the transparent substrate respectively. Optical detection is performed by measuring the reflected diffraction orders when the grating is illuminated through the quartz. The diffraction-based optical accelerometer is fabricated with silicon-glass anodic bonding procedure. This process is employed extensively in MEMS for its simplification and robustness. Experiment results show that the acceleration sensor has a displacement sensitivity of about 8 mV/nm and an acceleration sensitivity of about 5.6g-1 V. These results provide the reference for design and fabrication of the novel integrated micro-grating accelerometer.