Method of fabricating MEMS devices (such as IMod) comprising using a gas phase etchant to remove a layer
View Patent ↗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, wherein the MEMS comprises an interferometric modulator, further comprising forming a wall of the interferometric modulator on the deposited sacrificial layer prior to etching.
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 , further comprising chemically isolating the substrate from the MEMS.
4. 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, wherein the microelectromechanical device comprises an interferometric modulator and the microelectromechanical structure comprises a wall of the interferometric modulator.
5. The method of claim 4 , wherein the non-plasma gas phase etchant comprises at least one of XeF 2 , BrF 3 , ClF 3 , BrF 5 , and IF 5 .
6. The method of claim 4 , further comprising chemically isolating the substrate from the microelectromechanical device.
7. The method of claim 6 , wherein chemically isolating comprises depositing a thin film coating on the substrate.
8. The method of claim 1 , wherein the sacrificial layer comprises molybdenum.
9. The method of claim 1 , wherein the sacrificial layer comprises tungsten.
10. The method of claim 1 , wherein the sacrificial layer comprises tantalum.
11. The method of claim 4 , wherein the sacrificial layer comprises molybdenum.
12. The method of claim 4 , wherein the sacrificial layer comprises tungsten.
13. The method of claim 4 , wherein the sacrificial layer comprises tantalum.
14. The method of claim 1 , wherein the non-plasma gas phase etchant comprises XeF 2 .
15. The method of claim 4 , wherein the non-plasma gas phase etchant comprises XeF 2 .
16. The method of claim 1 , wherein the wall of the interferometric modulator is at least partially reflective and at least partially transmissive.
17. The method of claim 4 , wherein the wall of the interferometric modulator is at least partially reflective and at least partially transmissive.