Method and system for xenon fluoride etching with enhanced efficiency

• US 20060065622A1
• Filed: 03/17/2005
• Published: 03/30/2006
• Est. Priority Date: 09/27/2004
• Status: Abandoned Application

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Inventors: Floyd, Philip D., Cummings, William J.
• Application Number:
  US11/083,030
• Publication Number:
  US 20060065622A1
• Time in Patent Office: Days
• US Class Current: 216/58
• CPC Class Codes: B81B 2201/047 Optical MEMS not provided for in B81B2201/042 - B81B2201/045
• CPC Class Codes: B81C 1/00531 Dry etching
• CPC Class Codes: B81C 2201/0142 Processes for controlling etch progression not provided for in B81C2201/0136 - B81C2201/014
• CPC Class Codes: B81C 2201/056 Releasing structures at the end of the manufacturing process
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 21/32135 by vapour etching only
• CPC Class Codes: H01L 21/67069 for drying etching

Abstract

Provided herein is an apparatus and a method useful for manufacturing MEMS devices. An aspect of the disclosed apparatus provides a substrate comprising an etchable material exposed to a solid-state etchant, wherein the substrate and the solid-state etchant are disposed in an etching chamber. In some embodiments, the solid state etchant is moved into close proximity to the substrate. In other embodiments, a configurable partition is between the substrate and the solid-state etchant is opened. The solid-state etchant forms a gas-phase etchant suitable for etching the etchable material. In some preferred embodiments, the solid-state etchant is solid xenon difluoride. The apparatus and method are advantageously used in performing a release etch in the fabrication of optical modulators.

Claims

1. An apparatus for etching comprising an etching chamber and a etchant module, wherein

the etchant module is movable between a retracted position and an extended position,

in the retracted position, the etchant module is substantially outside the etching chamber, and

in the extended position the etchant module is substantially within the etching chamber.

2. The apparatus of claim 1, wherein the etching chamber comprises stainless steel.

3. The apparatus of claim 1, further comprising a substrate support.

4. The apparatus of claim 3, further comprising a optical sensor configured to detect the reflectance of a substrate on the substrate support.

5. The apparatus of claim 1, further comprising a faceplate, wherein the faceplate seals the etching chamber from the etchant module when the etchant module is in the retracted position.

6. The apparatus of claim 1, further comprising a purge system.

7. The apparatus of claim 1, wherein the movement of the module between the extended and the retracted position is automated.

8. The apparatus of claim 1, wherein etchant module comprises a platform configured to support solid xenon difluoride.

9. An apparatus for etching comprising:

an etching chamber,

a support for a substrate on which microelectromechanical device is formed,

an etchant module, and

a means for positioning the support and the etchant module in close proximity within the etching chamber.

10. The apparatus of claim 9, wherein the microelectromechanical systems device is an optical modulator.

11. An apparatus for etching comprising a chamber, a support for a substrate on which a microelectromechanical systems device is formed, and solid xenon difluoride, wherein the support and the solid xenon difluoride are disposed within the chamber.

12. The apparatus of claim 11, wherein the microelectromechanical systems device is an optical modulator.

13. An apparatus for etching comprising a support for a substrate on which a microelectromechanical systems device is formed and solid xenon difluoride, wherein the support and the solid xenon difluoride are sufficiently proximate for a vapor formed from the solid xenon difluoride to etch a substrate comprising an etchable material.

14. The apparatus of claim 13, wherein the distance between the support and the solid xenon difluoride is not more than 10 cm.

15. A method for fabricating a microelectromechanical systems device comprising:

disposing within an etching chamber a substrate comprising an etchable material, and

disposing within the etching chamber a solid etchant, wherein the solid etchant forms a gas-phase etchant capable of etching the etchable material.

16. The method of claim 15, wherein the microelectromechanical systems device is an optical modulator.

17. The method of claim 15, wherein the solid etchant is solid xenon difluoride.

18. The method of claim 15, wherein the etchable material comprises molybdenum.

19. The method of claim 15, wherein the etchable material comprises silicon.

20. A method for fabricating a microelectromechanical systems device comprising:

disposing a substrate within an etching chamber;

extending an etchant module into the etching chamber, wherein

a solid etchant is supported on the etchant module, and

the solid etchant forms a gas-phase etchant capable of etching a material on the substrate; and

allowing the gas-phase etchant to etch the material.

21. The method of claim 20, wherein the microelectromechanical systems device is an optical modulator.

22. The method of claim 20, wherein the solid etchant is solid xenon difluoride.

23. The method of claim 20, wherein the material on the substrate comprises molybdenum or silicon.

24. A microelectromechanical systems device fabricated according a method comprising:

disposing within an etching chamber a substrate comprising an etchable material and

disposing within the etching chamber a solid etchant, wherein the solid etchant forms a fluid etchant capable of etching the etchable material.

25. The microelectromechanical systems device of claim 24, wherein the microelectromechanical systems device is an optical modulator.

26. The microelectromechanical systems device of claim 24, wherein the solid etchant is solid xenon difluoride.

27. The microelectromechanical systems device of claim 24, wherein the etchable material comprises molybdenum.

28. The microelectromechanical systems device of claim 24, wherein the etchable material comprises silicon.

29. A method for fabricating a microelectromechanical systems device comprising:

providing solid xenon difluoride within an etch chamber;

supporting a substrate comprising an etchable material within the etch chamber; and

etching the etchable material from the substrate with a vapor generated by the solid xenon difluoride.

30. The method of claim 29, wherein the microelectromechanical systems device is an optical modulator.

31. The method of claim 29, wherein the etchable material comprises molybdenum or silicon.

32. A method for fabricating a microelectromechanical systems device comprising:

supporting a substrate comprising an etchable material within the etch chamber; and

positioning solid xenon difluoride sufficiently proximate to the substrate such that a vapor formed by the solid xenon difluoride etches the etchable material.

33. The method of claim 32, wherein the microelectromechanical systems device is an optical modulator.

34. The method of claim 32, wherein the etchable material comprises molybdenum or silicon.