Fig. 6: The micro-manufacturing and packaging process of the MOEMS gravimeter.
From: A μGal MOEMS gravimeter designed with free-form anti-springs
a Schematic diagram and b Photograph of the packaged device. c–i Schematic diagram of the manufacturing and packaging process. c1 A glass wafer. c2 Metal patterning of the grating on the glass wafer. d1 A silicon wafer of the mechanical sensing unit. d2 Metal patterning of the grating on the silicon wafer. d3 Lithography patterning of the mechanical sensing unit. d4 Deep reactive ion etching of the mechanical sensing unit. d5 Release of the mechanical sensing unit. d6 Processed mechanical sensing unit. e1 A glass wafer. e2 Deep wet etching of the glass wafer. f1 A silicon wafer of the substrate. f2 Platinum patterning on the silicon wafer. f3 Deep reactive ion etching of the confinement trench. g Low-stress bonding of wafer 2 and wafer 4. h Low-stress bonding of wafer 3 and the bonded wafer 2 + 4. i Low-stress bonding of wafer 1 and the bonded wafer 2 + 3 + 4.
