Emission microscope

• US 4,680,635 A
• Filed: 04/01/1986
• Issued: 07/14/1987
• Est. Priority Date: 04/01/1986
• Status: Expired due to Term

• Current Assignee: EDO Corporation (ITT, Inc.)
• Original Assignee: Intel Corporation
• Inventors: Khurana, Neeraj
• Primary Examiner(s): Britton, Howard W.
• Application Number:
  US06/846,874
• Time in Patent Office: 469 Days
• Field of Search: 358/211, 358/225, 358/101, 358/106, 358/93
• US Class Current: 348/79
• CPC Class Codes: G01R 31/2653 using electron beams
• CPC Class Codes: G02B 21/0004 specially adapted for specific applications
• CPC Class Codes: H04N 25/60 Noise processing, e.g. detecting, correcting, reducing or removing noise

Abstract

An emission microscope providing time resolution and high sensitivity to the viewing of light emitted from semiconductor devices is described. The present invention comprises a microscope optic system coupled to an image intensifier. An integrated circuit is viewed with the microscope optics and is stimulated with current flow. As a result of different phenomena, (oxide current, avalanching, and forward biased p-n junctions) light is emitted from the circuit. The image intensifier magnifies the light signal produced by the microscope optics. The output of the intensifier is coupled to a solid-state (CID or CCD) camera. The CID camera outputs a TV signal which is coupled to an image processing computer. The image processing computer controls image enhancement as well as noise reduction. The image processing computer is coupled to an output such as a monitor, a recorder, a printer, or any other suitable display.

Claims

1. A microscope comprising:

optical means comprising first and second lenses, said second lens for reducing the magnification of said first lens, said optical system outputting an optical image;

intensifier means coupled to said optical means, said intensifier means for intensifying said optical image and outputting an intensified image;

camera means coupled to said intensifier means for converting said intensified image to an electronic image signal;

processing means coupled to said camera means for removing noise from said electronic image signal and enhancing said electronic image signal;

display means coupled to said processing means for displaying a display image generated from said electronic image signal.

2. The microscope of claim 1 wherein said intensifier means comprises a photomultiplier for outputting a plurality of output electrons for each input electron.

3. The microscope of claim 2 wherein said photomultiplier comprises a plurality of microchannels.

4. The microscope of claim 1 wherein said intensifier means is gated such that said intensifier means is enabled for fixed periods of time.

5. The microscope of claim 1 wherein said camera means comprises a plurality of charge coupled devices disposed in an array.

6. The microscope of claim 1 wherein said camera means comprises a plurality of charge injected devices disposed in an array.

7. The microscope of claim 1 wherein said processing means comprises an image processing computer.

8. The microscope of claim 7 wherein said processing means integrates a plurality of electronic image signals to create a composite image.

9. The microscope of claim 8 wherein said processing means combines said image signals with a background image wherein landmarks of said electronic image signals may be identified.

10. The microscope of claim 1 wherein said display means comprises a television monitor.

11. The microscope of claim 1 wherein said intensifier means and said camera means are maintained at low temperatures so as to reduce thermionic emission of electrons.

12. The microscope of claim 1 wherein said microscope is used to detect infrared radiation produced by electroluminescent effects of silicon.

13. A device for magnifying and displaying output images of light emitted from semiconductor devices as a result of electrical stimulation, said device comprising:

optical means for viewing said semiconductor device, said optical means comprising a first objective lens for identifying said emitted light and a second lens for reducing the magnification of said first lens, said optical means outputting an optical image;

intensifier means coupled to said optical means for intensifying said optical image and outputting an intensified image;

camera means coupled to said intensifier means for converting said intensified image to a video image signal;

processing means coupled to said camera means for removing noise from said video image signal and enhancing said video image signal, said processing means outputting an enhanced image signal;

display means coupled to said processing means for displaying said output image generated from said enhanced image signal.

14. The device of claim 13 wherein said intensifying means comprises a plurality of microchannels, each of said microchannels outputting a plurality of electrons for each input electron.

15. The device of claim 13 wherein said intensifier means includes gating means for enabling said intensifier means for fixed periods of time.

16. The device of claim 13 wherein said camera comprises a plurality of charge coupled device disposed in an array.

17. The device of claim 13 wherein said camera means comprises a plurality of charge injected devices disposed in an array.

18. The device of claim 13 wherein said processing means integrates a plurality of said video image signals to create a composite video signal.

19. The device of claim 13 wherein said processing means combines said video image signal with a background image of said semiconductor device.

20. The device of claim 13 wherein said intensifier means and said camera means are maintained at low temperatues to reduce thermionic emission of electrons.

21. The device of claim 13 further including control means coupled to said processing means and said camera means, said control means for outputting a first signal to said processing means when said camera means reaches a saturation point.

22. The device of claim 21 further including frame storage means coupled to said processing means and said display means, said frame storage means for storing said video image signal and converting said video image signal to a digital signal.

23. A method for displaying light emitted from integrated circuits as a result of the electroluminesent effects of silicon, said method comprising the steps of:

passing said emitted light through an optical system, said optical system comprising first and second lenses, said second lens for reducing the magnification of said first lens;

passing the output of said optical system through an image intensifier, said image intensifier comprising a plurality of photomultiplier microchannels, said microchannels outputting plurality of electrons for each input electron;

converting said output of said image intensifier to a video image signal through use of a camera comprising a plurality of charge sensitive devices;

coupling said video image signal to a processing means, said processing means integrating a plurality of said video image signals, subtracting out background noise, and superimposing said integrated video image signals on a background image of said integrated circuit to produce a composite image;

displaying said composite image on a TV monitor coupled to said processing means.

24. The method of claim 23 further including the step of enabling said intensifier means for fixed periods of time to provide time resolution of said displayed images.