Inhibiting propagation of surface cracks in a MEMS Device

摘要

A microelectromechanical systems (MEMS) device (58) includes a structural layer (78) having a top surface (86). The top surface (86) includes surface regions (92, 94) that are generally parallel to one another but are offset relative to one another such that a stress concentration location (90) is formed between them. Laterally propagating shallow surface cracks (44) have a tendency to form in the structural layer (78), especially near the joints (102) between the surface regions (92, 94). A method (50) entails fabricating (52) the MEMS device (58) and forming (54) trenches (56) in the top surface (86) of the structural layer (78) of the MEMS device (58). The trenches (56) act as a crack inhibition feature to largely prevent the formation of deep cracks in structural layer (78) which might otherwise result in MEMS device failure.

主权项

1. A method comprising:
fabricating a microelectromechanical systems (MEMS) device that includes a structural layer having a surface, said surface including a first surface region and a second surface region adjacent to said first surface region, said first surface region lying in a first plane that is offset from a second plane of said second surface region, said second plane being substantially parallel to said first plane, said surface including at least one stress concentration location, said at least one stress concentration location including a longitudinal joint between said first and second surface regions; and forming at least one trench in said surface of said structural layer across said stress concentration location such that said at least one trench is formed in said surface of said structural layer across said longitudinal joint.