Photomask with detector for optimizing an integrated circuit production process and method of manufacturing an integrated circuit using the same

• US 20080261123A1
• Filed: 04/20/2007
• Published: 10/23/2008
• Est. Priority Date: 04/20/2007
• Status: Active Grant

• Current Assignee: Phototronics Incorporated
• Original Assignee: Phototronics Incorporated
• Inventors: Progler, Christopher
• Granted Patent: US 7,790,340 B2
• Time in Patent Office: Days
• US Class Current: 430/5
• CPC Class Codes: G03F 1/44 Testing or measuring features, e.g. grid patterns, focus monitors, sawtooth scales or notched scales

Abstract

A photomask for integrated circuit production comprising a substrate, one or more layers and a detector for monitoring a process parameter of the integrated circuit production in combination with one or more of the following: communication circuitry for communicating with external equipment for the integrated circuit production, a computational processor for analyzing the monitored process parameter, and a data storage component. In addition, a method of integrated circuit production comprising the steps of providing a photomask in the integrated circuit production process and monitoring a process parameter of the integrated circuit production using the photomask, in combination with one or more following steps: analyzing the monitored process parameter using the photomask; communicating the monitored process parameter from the photomask to external equipment involved in the integrated circuit production; and storing the monitored process parameter in the photomask. For example, the photomask embodying aspects of the present invention may monitor and track the process parameter of a stepper during the integrated circuit production. The monitored data may be analyzed against the production information to determine possible adjustment or alteration to the integrated circuit production steps.

Claims

1. A photomask for integrated circuit production comprising:

a substrate;

one or more layers;

a detector for monitoring a process parameter of the integrated circuit production; and

communication circuitry for communicating with external equipment for the integrated circuit production.

2. The photomask of claim 1, wherein the detector comprises one or more sensors for detecting optical radiation.

3. The photomask of claim 2, wherein the one or more sensors are designed to detect optical radiation from a wafer exposure scanner.

4. The photomask of claim 1, wherein the process parameter comprises a parameter of a stepper for the integrated circuit production.

5. The photomask of claim 1, wherein the one or more layers comprise an active portion and a non-active portion.

6. The photomask of claim 5, wherein the detector is positioned at the active portion.

7. The photomask of claim 5, wherein the detector is positioned at the non-active portion.

8. The photomask of claim 1, wherein the one or more layers comprise a patterned portion and a non-patterned portion.

9. The photomask of claim 8, wherein the detector is positioned at the patterned portion.

10. The photomask of claim 8, wherein the detector is positioned at the non-patterned portion.

11. The photomask of claim 8, wherein the detector is positioned at a predetermined distance from the patterned portion.

12. The photomask of claim 1, wherein the detector is positioned at the substrate.

13. The photomask of claim 1, further comprising a pellicle.

14. The photomask of claim 13, wherein the detector is positioned at least partially at the pellicle plane.

15. The photomask of claim 1, wherein the detector comprises at least one type of circuitry selected from the group consisting of:

circuitry for monitoring an exposure level, circuitry for monitoring a vibration, circuitry for monitoring a position, circuitry for monitoring illumination characteristics, circuitry for monitoring scattered light, circuitry for monitoring diffracted light, circuitry for measuring image characteristics in a reflected light mode, and circuitry for monitoring the physical location of the photomask.

16. The photomask of claim 1, wherein the communication circuitry comprises wireless communication circuitry.

17. The photomask of claim 1, wherein the communication circuitry comprises wired communication circuitry.

18. The photomask of claim 1, wherein the external equipment comprises at least one type of external equipment selected from the group consisting of:

photomask manufacturing equipment, wafer exposure equipment, a design automation tool, a simulation tool, a process control system, a logistical control system, a mask tracking system, a shipping system, a central database, a computer workstation, and a sensing station.

19. The photomask of claim 1, further comprising a computational processor for analyzing the monitored process parameter.

20. The photomask of claim 1, further comprising a data storage component.

21. The photomask of claim 20, wherein the data storage component comprises a flash memory.

22. The photomask of claim 20, wherein the data storage component comprises a memory for storing the monitored process parameter.

23. The photomask of claim 20, wherein the data storage component comprises a memory for storing photomask manufacturing information.

24. The photomask of claim 20, wherein the photomask manufacturing information comprises at least one type of information selected from the group consisting of:

pattern metrology data, a defect profile, registration information, critical dimensions, layout characteristics, image fidelity, and materials information.

25. The photomask of claim 20, wherein the data storage component comprises a memory for storing device layout information.

26. The photomask of claim 25, wherein the device layout information comprises at least one type of information selected from the group consisting of:

frequency composition of the layout, information relating to criticality of selected areas of the layout, and required tolerances for creating a functioning device.

27. The photomask of claim 1, wherein the detector comprises a photochemical detector.

28. The photomask of claim 27, wherein the photochemical detector comprises a photoresist.

29. The photomask of claim 27, wherein the communication circuitry comprises circuitry for communication signals recorded in the photochemical detector to stand-alone measurement equipement.

30. The photomask of claim 27, wherein the photochemical detector is positioned at a top surface of the photomask.

31. The photomask of claim 27, wherein the photochemical detector is positioned at a bottom surface of the photomask.

32. The photomask of claim 27, wherein the photochemical detector is positioned on a mask plane between the substrate and the one or more layers.

33. The photomask of claim 27, wherein the photochemical detector is positioned within the one or more layers.

34. The photomask of claim 27, further comprising a pellicle, wherein the photochemical recording medium is positioned in a pellicle plane.

35. The photomask of claim 1, further comprising a test structure for conditioning the process parameter to be monitored by the detector.

36. The photomask of claim 35, wherein the test structure is designed to diffract optical radiations.

37. The photomask of claim 36, wherein the test structure comprises a diffraction grating.

38. The photomask of claim 35, wherein the test structure is designed to reflect optical radiations.

39. The photomask of claim 35, wherein the test structure is designed to scatter optical radiations.

40. The photomask of claim 35, wherein the test structure is designed to direct optical radiation to the detector.

41. The photomask of claim 35, wherein the test structure is positioned at a top surface of the photomask.

42. The photomask of claim 35, wherein the test structure is positioned at a bottom surface of the photomask.

43. The photomask of claim 35, further comprising a pellicle, wherein the test structure is positioned at the pellicle plane.

44. The photomask of claim 35, wherein the test structure comprises moving parts.

45. The photomask of claim 35, wherein the test structure comprises an oscillating device.

46. The photomask of claim 35, wherein the test structure comprises an integrated microelectromechanical systems (MEMS) device.

47. The photomask of claim 1, further comprising a security system that prevents at least one of unauthorized use and copying of the photomask.

48. The photomask of claim 47, wherein the security system comprises at least a portion of the communication circuitry and transmits signals to one or more of the external equipment to validate connection of the photomask with the one or more external equipment.

49. The photomask of claim 48, wherein the signals are encrypted.

50. The photomask of claim 47, wherein the detector comprises one or more sensors, and the security system comprises at least one of the one or more sensors to detect characteristics of the photomask to ensure that the photomask was not subjected to at least one of manipulation and replacement.

51. The photomask of claim 50, wherein the at least one sensor is an optical sensor.

52. The photomask of claim 51, wherein the at least one sensor detects a scattered light thumbprint of the photomask.

53. The photomask of claim 47, wherein the security system comprises a blocking aperture.

54. The photomask of claim 53, wherein the blocking aperture is disposed on the photomask.

55. The photomask of claim 53, wherein the blocking aperture is disposed within the photomask.

56. The photomask of claim 53, wherein the blocking aperture is external to the photomask.

57. The photomask of claim 53, wherein the blocking aperture comprises a thin film.

58. The photomask of claim 57, wherein the thin film is an electrochromic film.

59. The photomask of claim 1, wherein the photomask is a binary photomask.

60. The photomask of claim 1, wherein the photomask is an embedded attenuated phase shift mask.

61. The photomask of claim 1, wherein the photomask is an alternating aperture phase shift mask.

62. A method of integrated circuit production comprising the steps of:

providing a photomask with circuitry in the integrated circuit production process;

monitoring a process parameter of the integrated circuit production using the photomask; and

analyzing the monitored process parameter using the photomask.

63. The method of claim 62, wherein the process parameter comprises at least one process parameter selected from the group consisting of:

optical radiation, exposure level, vibration, position, illumination characteristics, scattered light, diffracted light, image characteristics in a reflected light mode, and physical location of the photomask.

64. The method of claim 62, further comprising the step of adjusting the integrated circuit production process based on the result of the analyzing step.

65. The method of claim 62, wherein the analyzing step comprises the step of comparing the results of the monitoring step with expected results stored in a memory device associated with the photomask.

66. The method of claim 65, wherein photomask comprises the memory device.

67. The method of claim 62, wherein the analyzing step comprises the step of processing the monitored process parameter using computational logic.

68. The method of claim 62, further comprising the step of communicating the result of the analyzing step from the photomask to external equipment involved in the integrated circuit production.

69. The method of claim 68, wherein the external equipment comprises at least one type of equipment selected from the group consisting of:

photomask manufacturing equipment, wafer exposure equipment, a design automation tool, a simulation tool, a process control system, a central database, a computer workstation, and a sensing station.

70. The method of claim 62, further comprising the step of storing the monitored process parameter in the photomask.

71. The method of claim 62, further comprising the step of storing the result of the analyzing step in the photomask.

72. The method of claim 62, further comprising, prior to the monitoring step, the step of conditioning the process monitor to be monitored using the photomask.

73. The method of claim 72, wherein the conditioning step comprises the step of diffracting optical radiation using the photomask.

74. The method of claim 72, wherein the conditioning step comprises the step of reflecting optical radiation using the photomask.

75. The method of claim 72, wherein the conditioning step comprises the step of scattering optical radiation using the photomask.

76. The method of claim 72, wherein the conditioning step comprises the step of directing optical radiation toward a detection plane using the photomask.

77. The method of claim 62, wherein the step of monitoring comprises detecting the process parameter using electronic detection circuitry.

78. The method of claim 62, wherein the step of monitoring comprises detecting the process parameter using a photochemical detector.

79. The method of claim 78, wherein the photochemical detector comprises a photoresist.

80. The method of claim 62, further comprising a step of securing the photomask against at least one of unauthorized use and copying.

81. The method of claim 80, wherein the step of securing comprises transmitting signals to one or more of the external equipment to validate connection of the photomask with the one or more external equipment.

82. The method of claim 81, further comprising a step of encrypting the signals.

83. The method of claim 80, wherein the step of securing comprises detecting one or more characteristics of the photomask to ensure that the photomask was not subjected to at least one of manipulation and replacement.

84. The method of claim 83, wherein the one or more characteristics comprises a scattered light thumbprint of the photomask.

85. The method of claim 80, wherein the step of securing comprises selectively blocking the photomask with a blocking aperture.