Patent ID: 10906802

Abstract:
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.