Invensense, Inc.

Emad Mehdizadeh

Daesung Lee

Bongsang Kim

Nikhil Apte

Alan Cuthbertson

Mei-Lin Chan

Leonardo Baldasarre

Ian Flader

Chienliu Chang

Xiaoyue Jiang

Methods and systems for reducing stiction through roughening the surface and reducing the contact area in MEMS devices are disclosed. A method includes fabricating bumpstops on a surface of a MEMS device substrate to reduce stiction. Another method is directed to applying roughening etchant to a surface of a silicon substrate to enhance roughness after cavity etch and before removal of hardmask. Another embodiment described herein is directed to a method to reduce contact area between proof mass and UCAV ('upper cavity') substrate surface with minimal impact on the cavity volume by introducing a shallow etch process step and maintaining high pressure in accelerometer cavity. Another method is described as to increasing the surface roughness of a UCAV substrate surface by depositing a rough layer (e.g. polysilicon) on the surface of the substrate and etching back the rough layer to transfer the roughness.

Stiction reduction system and method thereof

A piezoelectric micromachined ultrasound transducer (PMUT) device may include a plurality of layers including a structural layer, a piezoelectric layer, and electrode layers located on opposite sides of the piezoelectric layer. Conductive barrier layers may be located between the piezoelectric layer and the electrodes to the prevent diffusion of the piezoelectric layer into the electrode layers.

Piezoelectric micromachined ultrasound transducer device with piezoelectric barrier layer

Growing community of inventors

San Jose, CA, United States of America

Emad Mehdizadeh