Ring oscillator system

• US 6,933,739 B1
• Filed: 05/23/2003
• Issued: 08/23/2005
• Est. Priority Date: 05/23/2003
• Status: Active Grant

• Current Assignee: Marvell Israel Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell Semiconductor Israel, Ltd.
• Inventors: Rosen, Eitan
• Primary Examiner(s): KARLSEN, ERNEST F
• Application Number:
  US10/444,901
• Time in Patent Office: 823 Days
• Field of Search: 324/763, 324/760, 324/765, 714/733, 714/734, 374/178, 374/183, 374/185
• US Class Current: 324/762.03
• CPC Class Codes: G01R 31/2884 using dedicated test connectors, test elements or test circuits on the IC under test G01R31/2855 takes precedence
• CPC Class Codes: H01L 22/34 Circuits for electrically characterising or monitoring manufacturing processes, e. g. whole test die, wafers filled with test structures, on-board-devices incorporated on each die, process control monitors or pad structures thereof, devices in scribe line switching, multiplexing, gating devices G01R19/25; process control with lithography, e.g. dose control, G03F7/20; structures for alignment control by optical means G03F7/70633

Abstract

Testing devices at various locations on a die may be used to determine one or more properties of the locations. For example, a testing device including an oscillator such as a ring oscillator at a location may be used to determine a silicon quality, temperature, and/or voltage at the location.

Claims

1. A method, comprising:

generating a signal indicative of one or more characteristics of a first location on a die;

measuring a parameter of the signal under at least two conditions that separate at least two die parameters; and

determining a characteristic of the first location based on the measuring.

2. The method of claim 1, wherein generating a signal comprises generating an oscillating signal.

3. The method of claim 2, wherein measuring a parameter of the signal comprises measuring the frequency of the oscillating signal.

4. The method of claim 3, wherein measuring the frequency of the oscillating signal comprises counting a number of oscillations in a sampling time.

5. The method of claim 1, wherein determining a characteristic of the first location based on the measuring comprises determining a silicon quality of the first location based on a frequency of an oscillator.

6. The method of claim 1, wherein determining a characteristic of the first location based on the measuring comprises determining a temperature of the first location based on a frequency of an oscillator.

7. The method of claim 6, wherein determining the temperature of the first location comprises turning off a clock to a circuit on the die, waiting a time interval, and subsequently determining the temperature based on the frequency.

8. The method of claim 6, wherein determining the temperature of the first location comprises measuring the frequency at a first time just after a clock to a circuit on the die is turned off, measuring the frequency at a second time after the clock to the circuit has been on for a thermal equilibrium time, and determining a difference between the frequency at the first time and the frequency at the second time.

9. The method of claim 1, wherein determining a characteristic of the first location based on the measuring comprises determining a voltage of the first location based on the frequency of an oscillator.

10. The method of claim 9, wherein determining the voltage comprises measuring the frequency at a first time just after a clock to a circuit on the die has been turned on.

11. The method of claim 9, wherein determining the voltage comprises measuring the frequency at a first time after a clock to a circuit on the die has been turned on for at least a thermal equilibrium time, measuring the frequency at a second time just after the clock to the circuit has been turned off, and determining a difference between the frequency at the first time and the frequency at the second time.

12. A system, comprising:

means for generating a signal indicative of one or more characteristics of a first location on a die;

means for measuring a parameter of the signal under at least two conditions that separate at least two die parameters; and

means for determining a characteristic of the first location based on the measuring.

13. The system of claim 12, wherein the means for generating a signal comprises means for generating an oscillating signal.

14. The system of claim 13, wherein the means for measuring a parameter of the signal comprises means for measuring the frequency of the oscillating signal.

15. The system of claim 14, wherein the means for measuring the frequency of the oscillating signal comprises means for counting a number of oscillations in a sampling time.

16. The system of claim 12, wherein the means for determining a characteristic of the first location based on the measuring comprises means for determining a silicon quality of the first location based on a frequency of an oscillator.

17. The system of claim 12, wherein the means for determining a characteristic of the first location based on the measuring comprises means for determining a temperature of the first location based on a frequency of an oscillator.

18. The system of claim 17, wherein the means for determining the temperature of the first location comprises means for turning off a clock to a circuit on the die, waiting a time interval, and subsequently determining the temperature based on the frequency.

19. The system of claim 17, wherein the means for determining the temperature of the first location comprises means for measuring the frequency at a first time just after a clock to a circuit on the die is turned off, measuring the frequency at a second time after the clock to the circuit has been on for a thermal equilibrium time, and determining a difference between the frequency at the first time and the frequency at the second time.

20. The system of claim 12, wherein the means for determining a characteristic of the first location based on the measuring comprises means for determining a voltage of the first location based on the frequency of an oscillator.

21. The system of claim 20, wherein the means for determining the voltage comprises means for measuring the frequency at a first time just after a clock to a circuit on the die has been turned on.

22. The system of claim 20, wherein the means for determining the voltage comprises means for measuring the frequency at a first time after a clock to a circuit on the die has been turned on for at least a thermal equilibrium time, measuring the frequency at a second time just after the clock to the circuit has been turned off, and determining a difference between the frequency at the first time and the frequency at the second time.

23. A method, comprising:

generating a signal indicative of one or more characteristics of a first location on a die;

measuring a parameter of the signal at two times; and

determining a characteristic of the first location based on the measuring, including separating effects of at least two die parameters based on the signal parameter measured at the two times.

24. The method of claim 23, wherein generating a signal comprises generating an oscillating signal.

25. The method of claim 24, wherein measuring a parameter of the signal comprises measuring the frequency of the oscillating signal.

26. The method of claim 25, wherein measuring the frequency of the oscillating signal comprises counting a number of oscillations in a sampling time.

27. The method of claim 23, wherein determining a characteristic of the first location based on the measuring comprises determining a silicon quality of the first location based on a frequency of an oscillator.

28. The method of claim 23, wherein determining a characteristic of the first location based on the measuring comprises determining a temperature of the first location based on a frequency of an oscillator.

29. The method of claim 28, wherein determining the temperature of the first location comprises turning off a clock to a circuit on the die, waiting a time interval, and subsequently determining the temperature based on the frequency.

30. The method of claim 28, wherein determining the temperature of the first location comprises measuring the frequency at a first time just after a clock to a circuit on the die is turned off, measuring the frequency at a second time after the clock to the circuit has been on for a thermal equilibrium time, and determining a difference between the frequency at the first time and the frequency at the second time.

31. The method of claim 23, wherein determining a characteristic of the first location based on the measuring comprises determining a voltage of the first location based on the frequency of an oscillator.

32. The method of claim 31, wherein determining the voltage comprises measuring the frequency at a first time just after a clock to a circuit on the die has been turned on.

33. The method of claim 31, wherein determining the voltage comprises measuring the frequency at a first time after a clock to a circuit on the die has been turned on for at least a thermal equilibrium time, measuring the frequency at a second time just after the clock to the circuit has been turned off, and determining a difference between the frequency at the first time and the frequency at the second time.

34. A system, comprising:

means for generating a signal indicative of one or more characteristics of a first location on a die;

means for measuring a parameter of the signal at two times; and

means for determining a characteristic of the first location based on the measuring, including means for separating effects of at least two die parameters based on the signal parameter measured at the two times.

35. The system of claim 34, wherein the means for generating a signal comprises means for generating an oscillating signal.

36. The system of claim 35, wherein the means for measuring a parameter of the signal comprises means for measuring the frequency of the oscillating signal.

37. The system of claim 36, wherein the means for measuring the frequency of the oscillating signal comprises means for counting a number of oscillations in a sampling time.

38. The system of claim 34, wherein the means for determining a characteristic of the first location based on the measuring comprises means for determining a silicon quality of the first location based on a frequency of an oscillator.

39. The system of claim 34, wherein the means for determining a characteristic of the first location based on the measuring comprises means for determining a temperature of the first location based on a frequency of an oscillator.

40. The system of claim 39, wherein the means for determining the temperature of the first location comprises means for turning off a clock to a circuit on the die, waiting a time interval, and subsequently determining the temperature based on the frequency.

41. The system of claim 39, wherein the means for determining the temperature of the first location comprises means for measuring the frequency at a first time just after a clock to a circuit on the die is turned off, measuring the frequency at a second time after the clock to the circuit has been on for a thermal equilibrium time, and determining a difference between the frequency at the first time and the frequency at the second time.

42. The system of claim 34, wherein the means for determining a characteristic of the first location based on the measuring comprises means for determining a voltage of the first location based on the frequency of an oscillator.

43. The system of claim 42, wherein the means for determining the voltage comprises means for measuring the frequency at a first time just after a clock to a circuit on the die has been turned on.

44. The system of claim 42, wherein the means for determining the voltage comprises means for measuring the frequency at a first time after a clock to a circuit on the die has been turned on for at least a thermal equilibrium time, measuring the frequency at a second time just after the clock to the circuit has been turned off, and determining a difference between the frequency at the first time and the frequency at the second time.