Scanning mirror assembly with a scanning mirror elevated above a mems actuator

Abstract

Embodiments of the disclosure include a method of scanning mirror assembly for an optical sensing system. The method may include bonding a first wafer that includes a handle to a second wafer that includes a scanning mirror layer and etching the first wafer to release the handle. The method may further include bonding a third wafer that includes an actuator layer to the second wafer, and etching the third wafer to form a first set of actuator features and a second set of actuator features from the actuator layer. The method may also include etching the second wafer to release the scanning mirror layer.

1 - 16 . (canceled) 
     
     
         17 . A method of forming a scanning mirror assembly, comprising:
 bonding a first wafer that includes a handle to a second wafer that includes a scanning mirror layer;   etching the first wafer to release the handle;   bonding a third wafer that includes an actuator layer to the second wafer;   etching the third wafer to form a first set of actuator features and a second set of actuator features from the actuator layer;   and   etching the second wafer to release the scanning mirror layer.   
     
     
         18 . The method of  claim 17 , further comprising:
 etching the first wafer to form the handle.   
     
     
         19 . The method of  claim 21 , further comprising:
 etching the fourth wafer to form the plurality of interconnects and the plurality of actuator anchors.   
     
     
         20 . The method of  claim 17 , wherein at least one of the first wafer, the second wafer, and the third wafer is a Silicon on Insulator (SOI) wafer. 
     
     
         21 . The method of  claim 17 , further comprising:
 bonding a fourth wafer that includes a plurality of interconnects and a plurality of actuator anchors to the first set of actuator features and the second set of actuator features.   
     
     
         22 . A method of forming a scanning mirror assembly, comprising:
 forming a handle in a first wafer bonded to a second wafer that includes a scanning mirror layer;   forming a microelectromechanical system (MEMS) actuator in a third wafer boned to the handle; and   forming a scanning mirror from the scanning mirror layer in the second wafer.   
     
     
         23 . The method of  claim 22 , wherein the handle has a predetermined thickness to keep the scanning mirror and the MEMS actuator at a predetermined distance apart. 
     
     
         24 . The method of  claim 22 , wherein forming the MEMS actuator in the third wafer further comprising:
 etching the third wafer to form a plurality of stator actuator features and a plurality of rotatable actuator features in the MEMS actuator.   
     
     
         25 . The method of  claim 24 , further comprising:
 forming a plurality of interconnects in a fourth wafer bonded to the third wafer, wherein the plurality of interconnects are bonded to the plurality of rotatable actuator features in the MEMS actuator.   
     
     
         26 . The method of  claim 25 , further comprising:
 forming a plurality of actuator anchors in the fourth wafer, wherein the plurality of actuator anchors are bonded to the plurality of stator actuator features in the MEMS actuator.   
     
     
         27 . The method of  claim 22 , wherein forming the scanning mirror from the scanning mirror layer in the second wafer further comprises:
 releasing the scanning mirror layer in the second wafer; and   depositing a film layer on the scanning mirror layer.   
     
     
         28 . The method of  claim 22 , wherein at least one of the first wafer, the second wafer, and the third wafer is a Silicon on Insulator (SOI) wafer. 
     
     
         29 . A scanning mirror assembly formed by a method, the method comprising:
 forming a handle in a first wafer bonded to a second wafer that includes a scanning mirror layer;   forming a microelectromechanical system (MEMS) actuator in a third wafer boned to the handle; and   forming a scanning mirror from the scanning mirror layer in the second wafer.   
     
     
         30 . The scanning mirror assembly of  claim 29 , wherein the handle has a predetermined thickness to keep the scanning mirror and the MEMS actuator at a predetermined distance apart. 
     
     
         31 . The scanning mirror assembly of  claim 29 , wherein the MEMS actuator comprises a plurality of stator actuator features and a plurality of rotatable actuator features both formed in the third wafer. 
     
     
         32 . The scanning mirror assembly of  claim 31 , wherein the plurality of rotatable actuator features is coupled to the handle and configured to rotate with the handle and the scanning mirror as a single unit. 
     
     
         33 . The scanning mirror assembly of  claim 31 , wherein the plurality of stator actuator features comprises a plurality of stator comb drive fingers and the plurality of rotatable actuator features comprises a plurality of rotatable comb drive fingers. 
     
     
         34 . The scanning mirror assembly of  claim 31 , wherein the method further comprises:
 forming a plurality of interconnects in a fourth wafer bonded to the third wafer, wherein the plurality of interconnects are coupled to the plurality of rotatable actuator features in the MEMS actuator.   
     
     
         35 . The scanning mirror assembly of  claim 34 , wherein the method further comprises:
 forming a plurality of actuator anchors in the fourth wafer, wherein the plurality of actuator anchors are coupled to the plurality of stator actuator features in the MEMS actuator and configured to maintain the plurality of stator actuator features in a stationary position.   
     
     
         36 . The scanning mirror assembly of  claim 29 , wherein forming the scanning mirror from the scanning mirror layer in the second wafer further comprises:
 releasing the scanning mirror layer in the second wafer; and   depositing a film layer on the scanning mirror layer.