Micro-electro-optical mechanical device having an implanted dopant included therein and a method of manufacture therefor

• US 6,522,801 B1
• Filed: 10/10/2000
• Issued: 02/18/2003
• Est. Priority Date: 10/10/2000
• Status: Expired due to Term

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Agere Systems Incorporated (Broadcom, Inc.), Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Ramirez, Ainissa, Jin, Sungho, Pardo, Flavio, Kim, Jungsang, Aksyuk, Vladimir A., Mavoori, Hareesh
• Primary Examiner(s): Healy, Brian
• Application Number:
  US09/685,883
• Time in Patent Office: 861 Days
• Field of Search: 385/18, 385/16, 385/17, 359/198, 359/245, 250/216
• US Class Current: 385/18
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81B 2203/0127 Diaphragms, i.e. structures separating two media that can control the passage from one medium to another; Membranes, i.e. diaphragms with filtering function
• CPC Class Codes: B81C 1/00666 Treatments for controlling internal stress or strain in MEMS structures
• CPC Class Codes: B81C 2201/0164 by doping the layer
• CPC Class Codes: G02B 2006/12104 Mirror; Reflectors or the like
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 6/122 Basic optical elements, e.g. light-guiding paths
• CPC Class Codes: G02B 6/266 the optical element being an attenuator

Abstract

The present invention provides a micro-electro-mechanical system (MEMS) optical device. The micro-electro-mechanical system (MEMS) optical device includes a mirror having a substrate with an implanted light reflective optical layer thereover, and a mounting substrate on which the mirror is movably mounted. The inclusion of the dopant within the light reflective optical layer increases the tensile stress of the device and tends to correct the concave curvature of the mirror structure toward a desirably flat configuration.

Claims

1. A micro-electro-mechanical system (MEMS) optical device, comprising:

a mirror having a light reflective optical layer containing at least one type of an implanted dopant located over a substrate; and

a mounting substrate on which the mirror is movably mounted.

2. The micro-electro-mechanical system (MEMS) optical device recited in claim 1 further including an adhesion layer located between the substrate and the light reflective optical layer.

3. The micro-electro-mechanical system (MEMS) optical device recited in claim 2 further including at least one type of dopant located within at least a portion of the adhesion layer and the substrate.

4. The micro-electro-mechanical system (MEMS) optical device recited in claim 3 wherein the dopant located within at least a portion of the adhesion layer is present in a concentration of at least about 1E14 atoms /cm³.

5. The micro-electro-mechanical system (MEMS) optical device recited in claim 4 wherein the dopant located within at least a portion of the adhesion layer is present in a concentration of at least 1E17 atoms/cm³.

6. The micro-electro-mechanical system (MEMS) optical device recited in claim 1 wherein the dopant concentration in the light reflective optical layer is at least about 1E15 atoms/cm³.

7. The micro-electro-mechanical system (MEMS) optical device recited in claim 1 wherein the at least one type of implanted dopant has a solid solubility in the light reflective optical layer that is less than about 1 atomic percent.

8. The micro-electro-mechanical system (MEMS) optical device recited in claim 7 wherein the solid solubility is less than about 0.3 atomic percent.

9. The micro-electro-mechanical system (MEMS) optical device recited in claim 1 wherein the light reflective optical layer comprises a material selected from the group consisting of gold, silver, rhodium, platinum, copper, aluminum or a combination thereof.

10. The micro-electro-mechanical system (MEMS) optical device recited in claim 9 wherein the doped light reflective optical layer is doped with silicon and wherein the dopant concentration in the light reflective optical layer ranges from about 1E15 atoms/cm³ to about 1E22 atoms/cm³.

11. The micro-electro-mechanical system (MEMS) optical device recited in claim 10 wherein the dopant concentration in the light reflective optical layer ranges from about 1e17/cm³ to about 1E20 atoms/cm³.

12. The micro-electro-mechanical system (MEMS) optical device recited in claim 1 wherein the light reflective optical layer comprises gold.

13. The micro-electro-mechanical system (MEMS) optical device recited in claim 12 wherein the at least one type of implanted dopant comprises one or more elements selected from the group consisting of:

substitutional elements including silicon, bismuth, strontium, barium, cadmium, tungsten, iridium, rhenium, rhodium, ruthenium, cobalt, sulfur, selenium, tellurium, chlorine, iodine, phosphorous;

interstitial elements including boron, carbon, nitrogen oxygen, fluorine and hydrogen;

rare earth group elements including cerium, europium, erbium, lanthanum, neodymium, samarium, terbium; and

gas atoms including helium, neon, argon and krypton.

14. The micro-electro-mechanical system (MEMS) optical device recited in claim 1 wherein the light reflective optical layer comprises silver.

15. The micro-electro-mechanical system (MEMS) optical device recited in claim 14 wherein the at least one type of implanted dopant comprises one or more elements selected from the group consisting of silicon, bismuth, strontium, barium, cadmium, chromium, tungsten, nickel, iridium, molybdenum, niobium, rhenium, rhodium, ruthenium, osmium, vanadium, cobalt, sulfur, selenium, tellurium, chlorine, phosphorous, boron, carbon, nitrogen, oxygen, fluorine, hydrogen, cerium, europium, gadolinium, lanthanum, neodymium, samarium, terbium, yttrium, helium, neon, argon and krypton.

16. The micro-electro-mechanical system (MEMS) optical device recited in claim 1 wherein the light reflective optical layer comprises aluminum.

17. The micro-electro-mechanical system (MEMS) optical device recited in claim 16 wherein the at least one type of implanted dopant comprises one or more elements selected from the group consisting of gold, barium, bismuth, cadmium, cobalt, chromium, iron, germanium, silicon, hafnium, vanadium, indium, iridium, molybdenum, nickel, lead, titanium, tungsten, palladium, platinum, rhenium, rhodium, ruthenium, sulfur, selenium, tellurium, antimony, tin, strontium, helium, neon, argon, krypton, chlorine, iodine, phosphorous, cerium, dysprosium, erbium, europium, gadolinium, holmium, lanthanum, lutetium, neodymium, samarium, terbium, yttrium, ytterbium, boron, carbon, nitrogen, oxygen, fluorine and hydrogen.

18. The micro-electro-mechanical system (MEMS) optical device as recited in claim 1 wherein the substrate comprises a material selected from the group consisting of polysilicon, single crystal silicon, silicon nitride, silicon carbide, silicon oxide, diamond film, or any regional and layered combination of these materials.

19. The micro-electro-mechanical system (MEMS) optical device as recited in claim 1 wherein at least one of the implanted dopants in the light reflective optical layer is in the form of isolated embedded atoms.

20. The micro-electro-mechanical system (MEMS) optical device as recited in claim 1 wherein at least one of the implanted dopants in the light reflective optical layer is in the form of clusters having a size ranging from about 1 nm to about 1000 nm.

21. The micro-electro-mechanical system (MEMS) optical device as recited in claim 20 wherein at least one of the implanted dopants in the light reflective optical layer is in the form of clusters having a size ranging from about 1 nm to about 100 nm.

22. A method of manufacturing a micro-electro-mechanical system (MEMS) optical device, comprising:

forming a mirror having a light reflective optical layer containing at least one type of an implanted dopant located over a substrate-;

-and

forming a mounting substrate on which the mirror is movably mounted.

23. The method as recited in claim 22 further including forming an adhesion layer between the substrate and the light reflective optical layer.

24. The method as recited in claim 23 further including implanting at least one type of dopant within at least a portion of the adhesion layer and the substrate.

25. The method recited in claim 24 wherein implanting at least one type of dopant includes implanting at least one type of dopant within at least a portion of the adhesion layer and the substrate at a concentration of at least about 1E14 atoms/cm³.

26. The method recited in claim 25 wherein implanting at least one type of dopant within at least a portion of the adhesion layer and the substrate at a concentration of at least about 1E14 atoms/cm³ includes implanting at least one type of dopant within at least a portion of the adhesion layer and the substrate at a concentration of at least about 1E17 atoms/cm³.

27. The method recited in claim 22 wherein the light reflective optical layer having at least one type of implanted dopant has a concentration of at least about 1E15 atoms/cm³.

28. The method recited in claim 22 wherein the mirror comprises a material selected from the group consisting of gold, silver, rhodium, platinum, copper, aluminum and a combination thereof.

29. The method recited in claim 28 wherein at least one type of an implanted dopant comprises silicon and the light reflective optical layer has a silicon dopant concentration ranging from about 1E15 atoms/cm³ to about 1E22 atoms/cm³.

30. The method recited in claim 29 wherein the silicon dopant concentration is about 1E20 atoms/cm³.

31. The method recited in claim 22 wherein the light reflective optical layer comprises gold.

32. The method recited in claim 31 wherein the light reflective optical layer comprises gold and includes an implanted dopant selected from the group consisting of:

substitutional elements including silicon, bismuth, strontium, barium, cadmium, tungsten, iridium, rhenium, rhodium, ruthenium, cobalt, sulfur, selenium, tellurium, chlorine, iodine, phosphorous;

interstitial elements including boron, carbon, nitrogen oxygen, fluorine and hydrogen;

rare earth group elements including cerium, europium, erbium, lanthanum, neodymium, samarium, terbium; and

gas atoms including helium, neon, argon and krypton.

33. The method recited in claim 22 wherein the light reflective optical layer comprises silver.

34. The method recited in claim 33 wherein the light reflective optical layer comprises silver and includes an implanted dopant selected from the group consisting of silicon, bismuth, strontium, barium, cadmium, chromium, tungsten, nickel, iridium, molybdenum, niobium, rhenium, rhodium, ruthenium, osmium, vanadium, cobalt, sulfur, selenium, tellurium, chlorine, phosphorous, boron, carbon, nitrogen, oxygen, fluorine, hydrogen, cerium, europium, gadolinium, lanthanum, neodymium, samarium, terbium, yttrium, helium, neon, argon and krypton.

35. The method recited in claim 22 wherein the light reflective optical layer comprises aluminum.

36. The method recited in claim 35 wherein the light reflective optical layer comprises aluminum and includes an implanted dopant selected from the group consisting of gold, barium, bismuth, cadmium, cobalt, chromium, iron, germanium, silicon, hafnium, vanadium, indium, iridium, molybdenum, nickel, lead, titanium, tungsten, palladium, platinum, rhenium, rhodium, ruthenium, sulfur, selenium, tellurium, antimony, tin, strontium, helium, neon, argon, krypton, chlorine, iodine, phosphorous, cerium, dysprosium, erbium, europium, gadolinium, holmium, lanthanum, lutetium, neodymium, samarium, terbium, yttrium, ytterbium, boron, carbon, nitrogen, oxygen, fluorine and hydrogen.

37. The method as recited in claim 22 wherein the substrate is polysilicon.

38. The method as recited in claim 22 wherein forming a mirror having a light reflective optical layer includes forming a mirror having a dopant located therein that is in the form of isolated embedded atoms.

39. The method as recited in claim 22 wherein forming a mirror having a light reflective optical layer includes forming a mirror having a dopant located therein that is in the form of clusters having a size ranging from about 1 nm to about 1000 nm.

40. The method as recited in claim 39 wherein the clusters have a size ranging from about 1 nm to about 100 nm.

41. The method as recited in claim 39 wherein forming a mirror having a dopant located therein that is in the form of clusters having a size ranging from about 1 nm to about 1000 nm includes subjecting the mirror to a heat treatment below about 400°

C.

42. The method as recited in claim 22 wherein forming a light reflective optical layer includes forming a light reflective optical layer using a process selected from the group consisting of evaporation, sputtering, electrochemical deposition, chemical vapor deposition, followed by an ion implantation doping process with one or more dopants.

43. The method as recited in claim 22 wherein forming a light reflective layer includes using an extraction voltage for doping the light reflective layer such that at least 60% of the implanted dopant gets trapped and retained in the light reflective layer, with the remaining dopant penetrating into the substrate.

44. The method as recited in claim 43 wherein at least 90% of the implanted dopant gets trapped.

45. The method as recited in claim 43 wherein the extraction voltage is in the range from about 2 KeV to about 1000 KeV.

46. The method as recited in claim 45 wherein the extraction voltage is in the range from about 10 KeV to about 50 KeV.

47. The method as recited in claim 22 wherein forming a mirror having at least one type of an implanted dopant includes subjecting the mirror to an ion implantation technique.

48. The method as recited in claim 22 wherein forming a mirror having at least one type of an implanted dopant includes subjecting the mirror to a shadow mask or lithographic patterning process.

49. An optical communications system, comprising:

input/output fiber bundles;

a micro-electro-mechanical structure, comprising;

a mirror having a light reflective optical layer containing at least one type of an implanted dopant located over a substrate; and

a mounting substrate on which the mirror is movably mounted;

imaging lenses interposed between the input/output fiber bundles and the micro-electro-mechanical structure; and

a reflector.

50. The optical communications system recited in claim 49 further including an adhesion layer located between the substrate and the light reflective optical layer.

51. The optical communications system recited in claim 49 wherein the at least one type of dopant is present in the light reflective optical layer in a concentration of at least about 1E15atoms/cm³.

52. The optical communications system recited in claim 49 wherein the doped light reflective optical layer comprises a material selected from the group consisting of gold, silver, rhodium, platinum, copper, aluminum or a combination thereof.

53. The optical communications system recited in claim 49 wherein the light reflective optical layer comprises gold.

54. The optical communications system recited in claim 53 wherein the at least one type of dopant comprises one or more dopants selected from the group consisting of:

substitutional elements including silicon, bismuth, strontium, barium, cadmium, tungsten, iridium, rhenium, rhodium, ruthenium, cobalt, sulfur, selenium, tellurium, chlorine, iodine and phosphorous;

interstitial elements including boron, carbon, nitrogen oxygen, fluorine and hydrogen;

rare earth group elements including cerium, europium, erbium, lanthanum, neodymium, samarium, terbium; and

gas atoms including helium, neon, argon and krypton.

55. The optical communications system recited in claim 49 wherein the light reflective optical layer comprises silver.

56. The optical communications system recited in claim 55 wherein the at least one type of dopant comprises one or more dopants selected from the group consisting of silicon, bismuth, strontium, barium, cadmium, chromium, tungsten, nickel, iridium, molybdenum, niobium, rhenium, rhodium, ruthenium, osmium, vanadium, cobalt, sulfur, selenium, tellurium, chlorine, phosphorous, boron, carbon, nitrogen, oxygen, fluorine, hydrogen, cerium, europium, gadolinium, lanthanum, neodymium, samarium, terbium, yttrium, helium, neon, argon and krypton.

57. The optical communications system recited in claim 49 wherein the light reflective optical layer comprises aluminum.

58. The optical communications system recited in claim 57 wherein the at least one type of dopant comprises one or more dopants selected from the group consisting of gold, barium, bismuth, cadmium, cobalt, chromium, iron, germanium, silicon, hafnium, vanadium, indium, iridium, molybdenum, nickel, lead, titanium, tungsten, palladium, platinum, rhenium, rhodium, ruthenium, sulfur, selenium, tellurium, antimony, tin, strontium, helium, neon, argon, krypton, chlorine, iodine, phosphorous, cerium, dysprosium, erbium, europium, gadolinium, holmium, lanthanum, lutetium, neodymium, samarium, terbium, yttrium, ytterbium, boron, carbon, nitrogen, oxygen, fluorine and hydrogen.

59. The optical communications system recited in claim 49 that comprises one or more devices selected from the group consisting of:

a micro-electro-mechanical system (MEMS) optical cross connect system;

an optical power gain equalizer system;

a wavelength division multiplexing telecommunications system;

a light signal switch in an optical communications system; and

a variable optical attenuator in an optical communications system.