Fig. 6: Process flow of the MEMS device.
a Hard mask, b trench isolation patterning, c trench filling with Si3N4, d metal interconnects on the front, e back hard mask with mass/beam patterns, f released device, g, h final packaged device, i the schematic cross section showing the trench isolation technique, j etched trench 97.3 µm deep and 3 µm wide, k top view of etched trench, l etched trench filled with SiN as the isolator, m DRIE etched structures before release, n a microscope image in which the metal trace and the isolation trench can be seen
