Electronic device with thin film structure

Abstract

A method for fabricating an electronic device includes the steps of: preparing a cavity defining sacrificial layer, at least the upper surface of which is covered with an etch stop layer; forming at least one first opening in the etch stop layer, thereby partially exposing the surface of the cavity defining sacrificial layer; etching the cavity defining sacrificial layer through the first opening, thereby defining a provisional cavity under the etch stop layer and a supporting portion that supports the etch stop layer thereon; and etching away a portion of the etch stop layer, thereby defining at least one second opening that reaches the provisional cavity through the etch stop layer and expanding the provisional cavity into a final cavity.

1 . An electronic device comprising: 
 a substrate with at least one cavity;    a thin film structure, which defines the upper surface of the cavity; and    a patterned thin film that is supported by the thin film structure,    wherein the thin film structure includes at least one hole, which is not overlapped by the patterned thin film and which reaches the cavity.    
   
   
       2 . The device of  claim 1 , wherein a convex portion is provided inside of the cavity and right under the hole so as to protrude toward the thin film structure.  
   
   
       3 . The device of  claim 1 , wherein a concave portion is provided inside of the cavity and right under the hole so as to protrude away from the thin film structure.  
   
   
       4 . The device of  claim 1 , wherein the patterned thin film is a bolometer, and wherein the electronic device functions as an infrared sensor.