Invensense, Inc.

Chienlu Chang

Daesung Lee

Bongsang Kim

Alan Cuthbertson

Dongyang Kang

Provided herein is a method including fusion bonding a handle wafer to a first side of a device wafer. Standoffs are formed on a second side of the device wafer. A first hardmask is deposited on the second side. A second hardmask is deposited on the first hardmask. A surface of the second hardmask is planarized. A photoresist is deposited on the second hardmask, wherein the photoresist includes a MEMS device pattern. The MEMS device pattern is etched into the second hardmask. The MEMS device pattern is etched into the first hardmask, wherein the etching stops before reaching the device wafer. The photoresist and the second hardmask are removed. The MEMS device pattern is further etched into the first hardmask, wherein the further etching reaches the device wafer. The MEMS device pattern is etched into the device wafer. The first hardmask is removed.

Actuator layer patterning with topography

Provided herein is a method including fusion bonding a handle wafer to a first side of a device wafer. A hardmask is deposited on a second side of the device wafer, wherein the second side is planar. The hardmask is etched to form a MEMS device pattern and a standoff pattern. Standoffs are formed on the device wafer, wherein the standoffs are defined by the standoff pattern. A eutectic bond metal is deposited on the standoffs, the device wafer, and the hardmask. A first photoresist is deposited and removed, such that the first photoresist covers the standoffs. The eutectic bond metal is etched using the first photoresist. The MEMS device pattern is etched into the device wafer. The first photoresist and the hardmask are removed.

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Los Altos, CA, United States of America

Chienlu Chang