Reducing MEMS stiction by deposition of nanoclusters

摘要

A mechanism for reducing stiction in a MEMS device by decreasing surface area between two surfaces that can come into close contact is provided. Reduction in contact surface area is achieved by increasing surface roughness of one or both of the surfaces. The increased roughness is provided by forming a micro-masking layer on a sacrificial layer used in formation of the MEMS device, and then etching the surface of the sacrificial layer. The micro-masking layer can be formed using nanoclusters. When a next portion of the MEMS device is formed on the sacrificial layer, this portion will take on the roughness characteristics imparted on the sacrificial layer by the etch process. The rougher surface decreases the surface area available for contact in the MEMS device and, in turn, decreases the area through which stiction can be imparted.

主权项

1. A method for manufacturing a microelectromechanical systems (MEMS) device, the method comprising:
forming a first polysilicon layer over a substrate; forming a sacrificial layer over the first polysilicon layer; forming a plurality of nanoclusters on the sacrificial layer; etching the sacrificial layer using a wet etch process subsequent to said forming the plurality of nanoclusters, wherein
the wet etch is selective to the sacrificial layer,the nanoclusters provide a micro-masking layer for said etching, andsaid etching increases roughness of the surface of the sacrificial layer as compared to the roughness of the surface upon said forming the sacrificial layer; removing the nanoclusters from the surface of the sacrificial layer; and forming a second polysilicon layer on the sacrificial layer subsequent to said etching the sacrificial layer, wherein said removing is performed subsequent to said etching and prior to said forming the second polysilicon layer.