Anti-stiction bottom cavity surface for micromachined ultrasonic transducer devices
AssigneeBfly Operations, Inc.
InventorsLingyun Miao, Keith G. Fife, Jianwei Liu, Jonathan M. Rothberg
Life of this patent
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Abstract
A method of forming an ultrasonic transducer device involves depositing a first layer on a substrate, depositing a second layer on the first layer, patterning the second layer at a region corresponding to a location of a transducer cavity, depositing a third layer that refills regions created by patterning the second layer, planarizing the third layer to a top surface of the second layer, removing the second layer, conformally depositing a fourth layer over the first layer and the third layer, defining the transducer cavity in a support layer formed over the fourth layer; and bonding a membrane to the support layer.
Claims20
A method of forming an ultrasonic transducer device, the method comprising:
- depositing a first layer on a substrate;
- depositing a second layer on the first layer;
- patterning the second layer at a region corresponding to a location of a transducer cavity;
- depositing a third layer that refills regions created by patterning the second layer;
- planarizing the third layer to a top surface of the second layer;
- removing the second layer;
- conformally depositing a fourth layer over the first layer and the third layer;
- defining the transducer cavity in a support layer formed over the fourth layer;
- and
- bonding a membrane to the support layer.
A method of forming an ultrasonic transducer device, the method comprising:
- depositing a first layer on a substrate;
- patterning the first layer at a region corresponding to a location of a transducer cavity;
- conformally depositing an additional layer of a same type as the first layer on the first layer and exposed portions of the substrate;
- conformally depositing a second layer on the additional layer of the same type as the first layer;
- conformally depositing a third layer on the second layer;
- conformally depositing a fourth layer on the third layer;
- planarizing the fourth layer to a top surface of the third layer;
- depositing a membrane support layer;
- defining the transducer cavity in the support layer, wherein exposed portions of the third layer and the fourth layer are removed;
- bonding a membrane to the support layer.
Dependencies are inferred from the claim text.