ETCHING PROCESSES USED IN MEMS PRODUCTION

• US 20090071933A1
• Filed: 09/12/2008
• Published: 03/19/2009
• Est. Priority Date: 09/14/2007
• Status: Abandoned Application

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Zion, Todd Lyle, Ho, Chok, Hertzler, Ben Ward, Gousev, Evgeni, Heald, David, Sasagawa, Teruo, Yan, Xiaoming, Floyd, Philip
• Application Number:
  US12/210,026
• Publication Number:
  US 20090071933A1
• Time in Patent Office: Days
• US Class Current: 216/13
• CPC Class Codes: B01D 2257/11 Noble gases
• CPC Class Codes: B01D 2257/2027 Fluorine
• CPC Class Codes: B01D 53/002 by condensation
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/32135 by vapour etching only

Abstract

The efficiency of an etching process may be increased in various ways, and the cost of an etching process may be decreased. Unused etchant may be isolated and recirculated during the etching process. Etching byproducts may be collected and removed from the etching system during the etching process. Components of the etchant may be isolated and used to general additional etchant. Either or both of the etchant or the layers being etched may also be optimized for a particular etching process.

Claims

1. A method of fabricating an electronic device, comprising:

providing an electronic device comprising a layer to be etched, the electronic device being located within an etch chamber;

exposing the sacrificial layer to an etchant, the etchant comprising a noble gas fluoride;

collecting gases from the etch chamber; and

processing the collected gases so as to separate the noble gas fluoride from the collected gases.

2. The method of claim 1, wherein the noble gas fluoride comprises XeF₂.

3. The method of claim 1, additionally comprising returning the separated noble gas fluoride to the etch chamber.

4. The method of claim 1, wherein the etchant further comprises O₂.

5. The method of claim 1, wherein processing the collected gases comprises separating the noble gas fluoride using a cold trap.

6. The method of claim 1, wherein processing the collected gases comprises separating the noble gas fluoride using a size discriminator.

7. The method of claim 1, additionally comprising purifying the separated noble gas fluoride.

8. The method of claim 1, additionally comprising releasing additional noble gas fluoride into the etch chamber during the process of exposing the sacrificial layer to the etchant to maintain the partial pressure of XeF₂ at a predetermined level.

9. The method of claim 1, wherein the layer to be etched comprises a sacrificial material.

10. The method of claim 1, wherein the electronic device comprises a MEMS device.

11. The method of claim 1, wherein the electronic device comprises an interferometric modulator.

12. A method of fabricating an electronic device, comprising

providing an electronic device comprising a layer to be etched, the electronic device being located within an etch chamber;

exposing the sacrificial layer to an etchant, the etchant comprising a noble gas fluoride;

collecting gases from the etch chamber; and

processing the collected gases so as to separate a noble gas.

13. The method of claim 12, wherein the noble gas fluoride comprises XeF₂, and wherein the noble gas comprises Xe.

14. The method of claim 12, wherein processing the collected gases so as to separate the noble gas comprises converting noble gas-containing species within the collected gases so as to obtain elemental noble gas.

15. The method of claim 14, wherein converting the noble gas-containing species comprises using at least one of:

a liquid bath converter, a solid bed converter, or a gas bath converter.

16. The method of claim 12, wherein processing the collected gases so as to separate the noble gas comprises exposing at least a portion of the gases from the etch chamber to an active agent which is configured to interact with a byproduct having a boiling point substantially close to that of the noble gas.

17. The method of claim 12, wherein processing the collected gases so as to separate the noble gas comprises using a cold trap.

18. The method of claim 12, wherein the electronic device comprises a MEMS device.

19. The method of claim 12, wherein the electronic device comprises an interferometric modulator.

20. An etching device for use in fabricating an electronic device, the etching device comprising:

an etch chamber for retaining an electronic device comprising a layer to be etched;

a storage chamber operably attached to the etch chamber wherein the storage chamber is configured to store an etchant, and wherein the etchant comprises a noble gas fluoride;

a separation component operably attached to the etch chamber, wherein the separation component is configured to isolate a noble gas-containing process gas.

21. The etching device of claim 20, wherein the noble gas fluoride comprises XeF₂.

22. The etching device of claim 20, wherein the noble gas-containing process gas comprises elemental noble gas.

23. The etching device of claim 20, wherein the noble gas-containing process gas comprises the noble gas fluoride.

24. The etching device of claim 20, wherein the separation component comprises a cold trap.

25. The etching device of claim 20, wherein the separation component comprises a size discriminator.