Method of producing microelectromechanical device with isolated microstructures

US7943525B2 · kind B2 · utility

Assignee

• Freeescale Semiconductor, Inc. · US

Inventors

• Lisa Z. Zhang · Gilbert, US
• Lisa H. Karlin · Chandler, US
• Ruben B. Montez · Cedar Park, US
• Woo Tae Park · Singapore, SG

Key dates

• Filing date: Dec 19, 2008
• Grant date: May 17, 2011
• Expiry date: Aug 31, 2029

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B81C1/00698
• WIPO field: Micro-structural and nano-technology
• WIPO sector: Chemistry

Abstract

A microelectromechanical systems (MEMS) device (20) includes a polysilicon structural layer (46) having movable microstructures (28) formed therein and suspended above a substrate (22). Isolation trenches (56) extend through the layer (46) such that the microstructures (28) are laterally anchored to the isolation trenches (56). A sacrificial layer (22) is formed overlying the substrate (22), and the structural layer (46) is formed overlying the sacrificial layer (22). The isolation trenches (56) are formed by etching through the polysilicon structural layer (46) and depositing a nitride (72), such as silicon-rich nitride, in the trenches (56). The microstructures (28) are then formed in the structural layer (46), and electrical connections (30) are formed over the isolation trenches (56). The sacrificial layer (22) is subsequently removed to form the MEMS device (20) having the isolated microstructures (28) spaced apart from the substrate (22).