Thin film resistor for use in medical devices and method of making same

• US 6,129,742 A
• Filed: 03/31/1999
• Issued: 10/10/2000
• Est. Priority Date: 03/31/1999
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Wu, Fan, McLaurin, Allen W., Henson, Kirk, Managhan, Doug G.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US09/281,910
• Time in Patent Office: 559 Days
• Field of Search: 128/899, 607/1, 607/5, 607/116, 600/509
• US Class Current: 607/1
• CPC Class Codes: A61N 1/02 Details

Abstract

A method for forming a thin film resistor includes providing a sputter target having one or more silicon containing components and chromium diboride. For example, the one or more silicon containing components may include silicon and/or silicon carbide. The resistor film is then sputter deposited on a surface using a nitrogen containing sputter gas. The resistor material generally is sputtered to a thickness in the range of about 125 Å to about 500 Å while maintaining a desirable sheet resistance. The resistor film may be used in one or more electrical circuits, such as in an implantable medical device.

Claims

1. A method for providing a medical device including at least one resistor, the method comprising the steps of:

providing a medical device having a housing;

providing one or more electrical circuits, wherein at least one of the one or more electrical circuits includes a resistor, and further wherein a composition of the resistor includes silicon, silicon carbide, and chromium diboride; and

enclosing the one or more electrical circuits within the housing of the medical device.

2. The method of claim 1, wherein the composition of the resistor further includes nitrogen.

3. The method of claim 1, wherein the resistor has a thickness in the range of about 125 Å

to about 500 Å

.

4. The method of claim 3, wherein the resistor has a thickness greater than about 300 Å

.

5. The method of claim 1, wherein the resistor has a temperature coefficient of resistance in the range of about -3000 ppm/°

C. to about +400 ppm/°

C.

6. The method of claim 5, wherein the resistor has a zero temperature coefficient of resistance.

7. The method of claim 1, wherein the resistor has a sheet resistance in the range of about 500 Ω

/sq to about 100 kΩ

/sq.

8. The method of claim 1, wherein the one or more electrical circuits include an electrical circuit of an implantable device selected from one of a pacemaker, a defibrillator, a pacemaker/cardioverter/defibrillator, a cardioverter/defibrillator, a brain stimulator, a neurostimulator, a muscle stimulator, a gastric stimulator, an implantable monitor, a hemodynamic monitor, and a drug pump.

9. A method for providing a medical device including at least one resistor, the method comprising the steps of:

providing a medical device having a housing;

providing one or more electrical circuits, wherein at least one of the one or more electrical circuits includes a resistor, wherein a composition of the resistor includes one or more silicon containing components and chromium diboride, and further wherein the resistor has a thickness in the range of about 125 Å

to about 500 Å

; and

enclosing the one or more electrical circuits within the housing of the medical device.

10. The method of claim 9, wherein the composition of the resistor further includes nitrogen.

11. The method of claim 9, wherein the one or more silicon components of the composition of the resistor include silicon and silicon carbide.

12. The method of claim 9, wherein the thickness is greater than 300 Å

.

13. The method of claim 9, wherein the resistor has a temperature coefficient of resistance in the range of about -3000 ppm/°

C. to about +400 ppm/°

C.

14. The method of claim 13, wherein the resistor has a zero temperature coefficient of resistance.

15. The method of claim 9, wherein the resistor has a sheet resistance in the range of about 500 Ω

/sq to about 100 kΩ

/sq.

16. The method of claim 9, wherein the one or more electrical circuits include an electrical circuit of an implantable device selected from one of a pacemaker, a defibrillator, a pacemaker/cardioverter/defibrillator, a cardioverter/defibrillator, a brain stimulator, a neurostimulator, a muscle stimulator, a gastric stimulator, an implantable monitor, a hemodynamic monitor, and a drug pump.

17. A medical device comprising one or more electrical circuits, wherein at least one of the one or more electrical circuits includes a resistor, and further wherein a composition of the resistor includes silicon, silicon carbide, and chromium diboride.

18. The device of claim 17, wherein the composition of the resistor further includes nitrogen.

19. The device of claim 17, wherein the resistor has a thickness in the range of about 125 Å

to about 500 Å

.

20. The device of claim 19, wherein the resistor has a thickness greater than about 300 Å

.

21. The device of claim 17, wherein the resistor has a temperature coefficient of resistance in the range of about -3000 ppm/°

C. to about +400 ppm/°

C.

22. The device of claim 21, wherein the resistor has a zero temperature coefficient of resistance.

23. The device of claim 17, wherein the resistor has a sheet resistance in the range of about 500 Ω

/sq to about 100 kΩ

/sq.

24. The device of claim 17, wherein the one or more electrical circuits include an electrical circuit of an implantable device selected from one of a pacemaker, a defibrillator, a pacemaker/cardioverter/defibrillator, a cardioverter/defibrillator, a brain stimulator, a neurostimulator, a muscle stimulator, a gastric stimulator, an implantable monitor, a hemodynamic monitor, and a drug pump.

25. A medical device comprising one or more electrical circuits, wherein at least one of the one or more electrical circuits includes a resistor, wherein a composition of the resistor includes one or more silicon containing components and chromium diboride, and further wherein the resistor has a thickness in the range of about 125 Å

to about 500 Å

.

26. The device of claim 25, wherein the composition of the resistor further includes nitrogen.

27. The device of claim 25, wherein the one or more silicon components of the composition of the resistor include silicon and silicon carbide.

28. The device of claim 25, wherein the thickness is greater than 300 Å

.

29. The device of claim 25, wherein the resistor has a temperature coefficient of resistance in the range of about -3000 ppm/°

C. to about +400 ppm/°

C.

30. The device of claim 29, wherein the resistor has a zero temperature coefficient of resistance.

31. The device of claim 25, wherein the resistor has a sheet resistance in the range of about 500 Ω

/sq to about 100 kΩ

/sq.

32. The device of claim 25, wherein the one or more electrical circuits include an electrical circuit of an implantable device selected from one of a pacemaker, a defibrillator, a pacemaker/cardioverter/defibrillator, a cardioverter/defibrillator, a brain stimulator, a neurostimulator, a muscle stimulator, a gastric stimulator, an implantable monitor, a hemodynamic monitor, and a drug pump.

33. A resistor comprising silicon, silicon carbide, and chromium diboride.

34. The resistor of claim 33, wherein the resistor further includes nitrogen.

35. The resistor of claim 34, wherein the resistor further includes hydrogen.

36. The resistor of claim 34, wherein the resistor has a temperature coefficient of resistance in the range of about -3000 ppm/°

C. to about +400 ppm/°

C.

37. The resistor of claim 36, wherein the resistor has a zero temperature coefficient of resistance.

38. The resistor of claim 33, wherein the resistor has a thickness in the range of about 125 Å

to about 500 Å

.

39. The resistor of claim 38, wherein the resistor has a thickness greater than about 300 Å

.

40. The resistor of claim 33, wherein the resistor has a sheet resistance in the range of about 500 Ω

/sq to about 100 kΩ

/sq.

41. A resistor comprising one or more silicon containing components and chromium diboride, wherein the resistor has a thickness in the range of about 125 Å

to about 500 Å

.

42. The resistor of claim 41, wherein the resistor further comprises nitrogen.

43. The resistor of claim 41, wherein the one or more silicon containing components of the composition of the resistor include silicon and silicon carbide.

44. The resistor of claim 41, wherein the thickness of the resistor is greater than about 300 Å

.

45. The resistor of claim 41, wherein the resistor has a temperature coefficient of resistance in the range of about -3000 ppm/°

C. to about +400 ppm/°

C.

46. The resistor of claim 41, wherein the resistor has a zero temperature coefficient of resistance.

47. The resistor of claim 41, wherein the resistor has a sheet resistance in the range of about 500 Ω

/sq to about 100 kΩ

/sq.

48. A method of forming a resistor on a surface, the method comprising the steps of:

providing a sputter target, wherein the sputter target has a composition including one or more silicon containing components and chromium diboride; and

sputter depositing a resistive material on the surface to a thickness in the range of about 125 Å

to about 500 Å

using a nitrogen containing sputter gas and the sputter target.

49. The method of claim 48, wherein the method further includes the step of annealing the sputter deposited resistive material in an anneal atmosphere.

50. The method of claim 49, wherein the step of annealing the sputter deposited resistive material includes annealing the deposited resistive material in an anneal atmosphere comprising at least nitrogen.

51. The method of claim 50, wherein the step of annealing the deposited resistive material in an anneal atmosphere comprising at least nitrogen includes annealing the deposited resistive material in an anneal atmosphere comprising nitrogen and hydrogen.

52. The method of claim 49, wherein the step of sputter depositing the resistive material includes adjusting the temperature coefficient of resistance of the resistive material in a range of about -3000 ppm/°

C. to about +400 ppm/°

C. by controlling the anneal atmosphere.

53. The method of claim 49, wherein the step of sputter depositing the resistive material includes adjusting the sheet resistance of the resistive material in a range of about 500 Ω

/sq to about 100 kΩ

/sq by controlling the anneal atmosphere.

54. The method of claim 49, wherein the step of annealing the deposited resistive material includes annealing the deposited resistive material in at an anneal temperature in the range of about 425°

C. to about 600°

C.

55. The method of claim 54, wherein the step of sputter depositing the resistive material includes adjusting the temperature coefficient of resistance of the resistive material in a range of about -3000 ppm/°

C. to about +400 ppm/°

C. by controlling the anneal temperature.

56. The method of claim 54, wherein the step of sputter depositing the resistive material includes adjusting the sheet resistance of the resistive material in a range of about 500 Ω

/sq to about 100 kΩ

/sq by controlling the anneal temperature.

57. The method of claim 48, wherein the composition of the sputter target includes the one or more silicon containing components at an atomic weight percent in the range of about 40 percent to about 80 percent and the chromium diboride at an atomic weight percent of about 20 percent to about 60 percent.

58. The method of claim 57, wherein the one or more silicon containing components of the sputter target include silicon and silicon carbide.

59. The method of claim 58, wherein the one or more silicon containing components of the sputter target include the silicon at an atomic weight percent in the range of about 25 percent to about 45 percent and the silicon carbide at an atomic weight percent of about 15 percent to about 35 percent.

60. The method of claim 48, wherein the step of sputter depositing the resistive material on the surface includes sputter depositing the resistive material on the surface in a sputter atmosphere of a nitrogen and argon containing sputter gas.

61. The method of claim 60, wherein the nitrogen and argon containing sputter gas includes a nitrogen:

argon sputter gas at a ratio in the range of about 0 to about 0.3.

62. The method of claim 60, wherein the step of sputter depositing the resistive material includes adjusting the temperature coefficient of resistance of the resistive material in a range of about -3000 ppm/°

C. to about +400 ppm/°

C. by controlling the sputtering atmosphere.

63. The method of claim 60, wherein the step of sputter depositing the resistive material includes adjusting the sheet resistance of the resistor in a range of about 500 Ω

/sq to about 100 kΩ

/sq by controlling the sputtering atmosphere.

64. The method of claim 48, wherein the method further includes the step of patterning the resistive material.

65. A method of forming a resistor, the method comprising the steps of:

providing a surface;

exposing the surface to one or more sources of silicon, silicon carbide, chromium diboride, and nitrogen to form a resistive material on the surface; and

annealing the resistive material.

66. The method of claim 65, wherein exposing the surface to one or more sources of silicon, silicon carbide, chromium diboride, and nitrogen includes:

providing a sputter target in a chamber, wherein the sputter target

has a composition including silicon, silicon carbide, and chromium diboride; and

sputter depositing the resistive material on the surface using the sputter target and a sputter gas.

67. The method of claim 66, wherein the composition of the sputter target includes the silicon at an atomic weight percent in the range of about 25 percent to about 45 percent, the silicon carbide at an atomic weight percent of about 15 to about 35 percent, and the chromium diboride at an atomic weight percent of about 20 percent to about 60 percent.

68. The method of claim 66, wherein the step of exposing the surface to one or more sources of silicon, silicon carbide, chromium diboride, and nitrogen to form a resistive material on the substrate surface includes depositing the resistive material to a thickness in the range of about 125 Å

to about 500 Å

.

69. The method of claim 66, wherein the step of annealing the resistive material includes annealing the resistive material in an anneal atmosphere comprising at least nitrogen.

70. The method of claim 69, wherein the step of annealing the resistive material in an anneal atmosphere comprising at least nitrogen includes annealing the resistive material in an anneal atmosphere comprising nitrogen and hydrogen.

71. The method of claim 70, wherein the step of sputter depositing the resistive material includes adjusting the temperature coefficient of resistance of the resistive material in a range of about -3000 ppm/°

C. to about +400 ppm/°

C. by controlling the anneal atmosphere.

72. The method of claim 70, wherein the step of sputter depositing the resistive material includes adjusting the sheet resistance of the resistive material in a range of about 500 Ω

/sq to about 100 kΩ

/sq by controlling the anneal atmosphere.

73. The method of claim 66, wherein the step of annealing the resistive material includes annealing the deposited resistive material at an anneal temperature in the range of about 425°

C. to about 600°

C.

74. The method of claim 73, wherein the step of sputter depositing the resistive material includes adjusting the temperature coefficient of resistance of the resistive material in a range of about -3000 ppm/°

C. to about +400 ppm/°

C. by controlling the anneal temperature.

75. The method of claim 73, wherein the step of sputter depositing the resistive material includes adjusting the sheet resistance of the resistive material in a range of about 500 Ω

/sq to about 100 kΩ

/sq by controlling the anneal temperature.

76. The method of claim 66, wherein the step of sputter depositing the resistive material on the surface includes sputter depositing the resistive material on the surface in a sputter atmosphere of at least nitrogen.

77. The method of claim 76, wherein the step of sputter depositing the resistive material on the surface includes sputter depositing the resistive material on the surface in a sputter atmosphere of nitrogen and argon, and further wherein the nitrogen and argon containing sputter gas includes a nitrogen:

argon sputter gas at a ratio in the range of about 0 to about 0.3.

78. The method of claim 76, wherein the step of sputter depositing the resistive material includes adjusting the temperature coefficient of resistance of the resistive material in a range of about -3000 ppm/°

C. to about +400 ppm/°

C. by controlling the sputtering atmosphere.

79. The method of claim 76, wherein the step of sputter depositing the resistive material includes adjusting the sheet resistance of the resistor in a range of about 500 Ω

/sq to about 100 kΩ

/sq by controlling the sputtering atmosphere.

80. The method of claim 65, wherein the method further includes the step of patterning the resistive material.