METHOD OF FABRICATING MEMS DEVICES (SUCH AS IMod) COMPRISING USING A GAS PHASE ETCHANT TO REMOVE A LAYER

Abstract

Improvements in an interferometric modulator that cavity defined by two walls.

1 . A method of fabricating a microelectromechanical structure (MEMS), the method comprising etching a deposited sacrificial layer with a non-plasma gas phase etchant, wherein the sacrificial layer comprises at least one of molybdenum, tungsten, or tantalum. 
     
     
         2 . The method of  claim 1 , wherein the non-plasma gas phase etchant comprises at least one of XeF 2 , BrF 3 , ClF 3 , BrF 5 , and IF 5 . 
     
     
         3 . The method of  claim 1 , wherein the MEMS comprises an interferometric modulator, further comprising forming a wall of an interferometric modulator on a substrate and etching the deposited sacrificial layer from between the wall and the substrate. 
     
     
         4 . The method of  claim 1 , wherein the MEMS is formed over a substrate which is chemically isolated from the MEMS by an inert film coating. 
     
     
         5 . The method of  claim 1 , wherein the sacrificial layer comprises molybdenum. 
     
     
         6 . The method of  claim 1 , wherein the sacrificial layer comprises tungsten. 
     
     
         7 . The method of  claim 1 , wherein the sacrificial layer comprises tantalum. 
     
     
         8 . The method of  claim 1 , wherein the non-plasma gas phase etchant comprises XeF 2 . 
     
     
         9 . A method of forming a movable microelectromechanical device comprising:
 disposing a sacrificial layer on a substrate, wherein the sacrificial layer comprises at least one of molybdenum, tungsten, or tantalum;   disposing a microelectromechanical structure over the sacrificial layer and the substrate, the microelectromechanical structure comprising at least one thin film; and   etching the sacrificial layer with a non-plasma gas phase etchant to release the microelectromechanical structure from the sacrificial layer.   
     
     
         10 . The method of  claim 9 , wherein the non-plasma gas phase etchant comprises at least one XeF 2 , BrF 3 , C 1 F 3 , BrF 5 , and IF 5 . 
     
     
         11 . The method of  claim 9 , wherein the microelectromechanical device comprises an interferometric modulator. 
     
     
         12 . The method of  claim 9 , further comprising chemically isolating the substrate from the microelectromechanical device. 
     
     
         13 . The method of  claim 12 , wherein chemically isolating comprises depositing a thin film coating on the substrate. 
     
     
         14 . The method of  claim 9 , wherein the sacrificial layer comprises molybdenum. 
     
     
         15 . The method of  claim 9 , wherein the sacrificial layer comprises tungsten. 
     
     
         16 . The method of  claim 9 , wherein the sacrificial layer comprises tantalum. 
     
     
         17 . The method of  claim 9 , wherein the non-plasma gas phase etchant comprises XeF 2 . 
     
     
         18 . A method of making an array of microelectromechanical structures on a production line comprising micromachining electromechanical structures on a surface of a glass or plastic substrate that is at least as large as 8″×8″ or at least as large as 8″ in diameter. 
     
     
         19 . The method of  claim 18 , in which electronic features are fabricated in conjunction with the microelectromechanical structures. 
     
     
         20 . The method of  claim 19 , in which steps of fabricating the electronic features are overlapping with one or more of the steps of micromachining the structures. 
     
     
         21 . The method of  claim 19 , in which steps of fabricating the electronic features are non-overlapping with the steps of micromachining the structures. 
     
     
         22 . The method of  claim 18 , in which the microelectromechanical structures comprise interferometric modulators.