Apparatus and method for dynamic diagnostic testing of integrated circuits

• US 6,859,031 B2
• Filed: 08/26/2002
• Issued: 02/22/2005
• Est. Priority Date: 02/01/2002
• Status: Expired due to Fees

• Current Assignee: Credence Systems Corporation (COHU Incorporated)
• Original Assignee: Credence Systems Corporation (COHU Incorporated)
• Inventors: Goldberger, Itzik, Kasapi, Steven, Pakdaman, Nader
• Primary Examiner(s): Niebling, John F.
• Assistant Examiner(s): STEVENSON, ANDRE C
• Application Number:
  US10/229,181
• Publication Number:
  US 20030146761A1
• Time in Patent Office: 911 Days
• Field of Search: 324/752, 324/233, 324/483
• US Class Current: 324/233
• CPC Class Codes: G01R 31/311 of integrated circuits G01R31/31728 takes precedence
• CPC Class Codes: G01R 31/318505 Test of Modular systems, e.g. Wafers, MCM's
• CPC Class Codes: G01R 31/318511 Wafer Test

Abstract

Systems and methods consistent with principles of the present invention allow contactless measuring of various kinds of electrical activity within an integrated circuit. The invention can be used for high-bandwidth, at speed testing of various devices on a wafer during the various stages of device processing, or on packaged parts at the end of the manufacturing cycle. Power is applied to the test circuit using conventional mechanical probes or other means, such as CW laser light applied to a photoreceiver provided on the test circuit. The electrical test signal is introduced into the test circuit by stimulating the circuit using a contactless method, such as by directing the output of one or more modelocked lasers onto high-speed receivers on the circuit, or by using a high-speed pulsed diode laser. The electrical activity within the circuit in response to the test signal is sensed by a receiver element, such as a time-resolved photon counting detector, a static emission camera system, or by an active laser probing system. The collected information is used for a variety of purposes, including manufacturing process monitoring, new process qualification, and model verification.

Claims

1. An apparatus for measuring electrical characteristics of an integrated circuit, said integrated circuit comprising predetermined patterns of active electronic elements disposed on a surface of a semiconductor wafer, said apparatus comprising:

a stimulating energy source for injecting a test signal into said integrated circuit by stimulating predetermined areas of said integrated circuit;

power source for supplying power to at least one of said active electronic elements of said integrated circuit; and

a detector for detecting an electrical activity within sad integrated circuit in response to said injected test signal, wherein said responsive electrical activity comprises switching of at least one of said active electronic elements of said integrated circuit and wherein said characteristics on said integrated circuit are determined based on said detected electrical activity.

2. The apparatus of claim 1, wherein said detector operates to detect said electrical activity in said integrated circuit in an electrically non-loading manner.

3. The apparatus of claim 1, wherein said stimulating energy source operates to inject said test signal without establishing a mechanical contact with said predetermined stimulated areas of said integrated circuit.

4. The apparatus of claim 1, wherein said stimulating energy source stimulates said predetermined areas of said integrated circuit by directing a beam of electromagnetic radiation onto said predetermined areas.

5. The apparatus of claim 1, wherein said predetermined areas of said integrated circuit are stimulated using a beam of charged particles emitted by said stimulating energy source.

6. The apparatus of claim 1, wherein said test signal injected into said circuit is conditioned using a signal conditioning device disposed within said integrated circuit.

7. The apparatus of claim 1, wherein before said injecting, said integrated circuit is located on a wafer and positioned in a predetermined manner with respect to said stimulating energy source and said detector.

8. The apparatus of claim 7, wherein said integrated circuit is located on said wafer using an image of said wafer and performing an optical pattern recognition analysis of said image.

9. The apparatus of claim 7, wherein said integrated circuit is positioned with respect to said stimulating energy source and said detector using a mechanical stage.

10. The apparatus of claim 1, wherein before said injecting, an electrical power is supplied to said integrated circuit.

11. The apparatus of claim 10, wherein said electrical power is supplied to said integrated circuit by disposing a photoreceiver within said circuit and irradiating said photoreceiver using an energy beam.

12. The apparatus of claim 10, wherein said electrical power is supplied to said integrated circuit using at least one mechanical probe engaging at least one conducting pad disposed within said integrated circuit.

13. The apparatus of claim 1, wherein said injecting is performed after deposition of a metal layer of said integrated circuit.

14. The apparatus of claim 1, further comprising a setup for performing parametric measurements on said integrated circuit, wherein results of said parametric measurements are used in determining characteristics of said integrated circuit.

15. The apparatus of claim 1, wherein said detecting of electrical activity within said integrated circuit is performed using a non-time-resolved detection of photons emitted by said integrated circuit.

16. The apparatus of claim 1, wherein said detecting of electrical activity within said integrated circuit is performed using a time-resolved detection of photons emitted by said integrated circuit.

17. The apparatus of claim 1, wherein said detecting of electrical activity within said integrated circuit is performed using a laser beam probing of said integrated circuit.

18. The apparatus of claim 1, wherein said detecting of electrical activity within said integrated circuit is performed using at least one mechanical probe engaging at least one conducting pad disposed within said integrated circuit.

19. The apparatus of claim 1, wherein said detecting of electrical activity within said integrated circuit is performed using an electron-beam probing of said integrated circuit.