MEMS DEVICE HAVING VARIABLE GAP WIDTH AND METHOD OF MANUFACTURE

摘要

A MEMS device (40) includes a base structure (42) and a microstructure (44) suspended above the structure (42). The base structure (42) includes an oxide layer (50) formed on a substrate (48), a structural layer (54) formed on the oxide layer (50), and an insulating layer (56) formed over the structural layer (54). A sacrificial layer (112) is formed overlying the base structure (42), and the microstructure (44) is formed in another structural layer (116) over the sacrificial layer (112). Methodology (90) entails removing the sacrificial layer (112) and a portion of the oxide layer (50) to release the microstructure (44) and to expose a top surface (52) of the substrate (48). Following removal, a width (86) of a gap (80) produced between the microstructure (44) and the top surface (52) is greater than a width (88) of a gap (84) produced between the microstructure (44) and the structural layer (54).

主权项

1. A microelectromechanical systems (MEMS) device comprising:
a base structure including a substrate having a first dielectric layer formed thereon, a first structural layer formed on said first dielectric layer, and a second dielectric layer formed over said first structural layer, wherein an exposed region of a top surface of said substrate is exposed from each of said first dielectric layer, said first structural layer, and said second dielectric layer; and a proof mass suspended above said base structure to yield a first gap between said proof mass and said exposed region of said top surface of said substrate and a second gap between said proof mass and said first structural layer, a first width of said first gap being greater than a second width of said second gap.