Multi-level mems process
AssigneeInvenSense, Inc.
InventorsRoberto Martini, Matthew Julian Thompson, Giacomo Gafforelli, Luca Coronato, Luigi Esposito
Life of this patent
Estimating the term…
Abstract
An actuator layer of a MEMS sensor is be fabricated to include multi-level features, such as additional sense electrodes, vertical bump stops, or weighted proof masses. A sacrificial layer is deposited on the actuator layer such that locations are provided for the multi-level features to extend vertically from the actuator layer. After the multi-layer features are fabricated on the actuator layer the sacrificial layer is removed. Additional processing such as patterning of the actuator layer may be performed to provide desired functionality and electrical signals to portions of the actuator layer, including to the multi-level features.
Claims18
A method of fabricating a multi-level microelectromechanical system (MEMS) sensor, comprising:
- providing an actuator layer;
- applying a sacrificial layer to a first surface of the actuator layer, wherein one or more openings within the sacrificial layer correspond to one or more multi-level features;
- fabricating the one or more multi-level features on the actuator layer, wherein the one or more multi-level features extend from the first surface of the actuator layer through the one or more openings in the sacrificial layer;
- removing the sacrificial layer, wherein after removal of the sacrificial layer an intra-layer cavity separates a portion of the first surface of the actuator layer from the one or more multi-level features;
- bonding a handle layer overlying the multi-level features to the actuator layer, wherein after the bonding of the handle layer a cavity is formed over the multi-level features;
- and
- bonding a substrate layer to at least a portion of a second surface of the actuator layer, wherein after the bonding of the substrate layer a patterned portion of the actuator layer is suspended over the substrate layer.
Dependencies are inferred from the claim text.