Integrated circuit chips, apparatuses for obtaining backscatter data from samples, methods of backscatter analysis, and methods of forming alpha particle emission and detection systems

• US 7,557,345 B2
• Filed: 04/18/2007
• Issued: 07/07/2009
• Est. Priority Date: 04/18/2007
• Status: Expired due to Fees

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Williamson, Mark, Sandhu, Gurtej S.
• Primary Examiner(s): Porta; David P
• Assistant Examiner(s): Kim; Kiho
• Application Number:
  US11/787,852
• Publication Number:
  US 20080258057A1
• Time in Patent Office: 811 Days
• Field of Search: 250/308, 250/83, 250/71, 250/65, 257/428, 257/429, 257/781, 438/7
• US Class Current: 250/308
• CPC Class Codes: H01L 31/115 Devices sensitive to very short wavelength, e.g. X-rays, gamma-rays or corpuscular radiation

Abstract

Some embodiments include methods for fabricating an alpha particle emitter and detector associated with an integrated circuit chip. Some embodiments include an integrated circuit chip comprising an alpha particle emitter and detector supported by a semiconductor substrate. Some embodiments include an apparatus for obtaining backscatter data from a sample utilizing an alpha particle emission and detection system supported by a semiconductor substrate. Some embodiments include methods of backscatter analysis utilizing a semiconductor substrate containing an alpha particle emitter and an alpha particle sensor.

Claims

1. An integrated circuit chip, comprising:

a semiconductor substrate;

an alpha particle emitter supported by the substrate;

an alpha particle detector supported by the substrate; and

wherein the alpha particle emitter comprises one or both of radium and americium.

2. An integrated circuit chip, comprising:

a semiconductor substrate;

an alpha particle emitter supported by the substrate;

an alpha particle detector supported by the substrate; and

a magnetic lens supported by the substrate and configured for focusing alpha particles emitted from the emitter.

3. An integrated circuit chip, comprising:

a semiconductor substrate;

an alpha particle emitter supported by the substrate;

an alpha particle detector supported by the substrate; and

shielding between the alpha particle emitter and the alpha particle detector.

4. The integrated circuit chip of claim 3 wherein the shielding comprises one or both of platinum and gold.

5. The integrated circuit chip of claim 3 wherein the shielding consists of gold.

6. The integrated circuit chip of claim 3 wherein the alpha particle emitter, alpha particle detector, and shielding are together comprised by a unit cell;

and wherein the unit cell comprises a plurality of detectors and a single emitter.

7. The integrated circuit chip of claim 3 wherein the alpha particle emitter, alpha particle detector, and shielding are together comprised by a unit cell;

and wherein the unit cell comprises an emitter surrounding a detector.

8. The integrated circuit chip of claim 3 wherein the alpha particle emitter, alpha particle detector, and shielding are together comprised by a unit cell consuming an area of semiconductor real estate of less than or equal to about 20 microns².

9. The integrated circuit chip of claim 8 wherein the unit cell is radially symmetric.

10. The integrated circuit chip of claim 8 wherein the consumed area of semiconductor real estate is less than or equal to about 10 microns².

11. (The integrated circuit chip of claim 8 comprising an array of the unit cells.

12. An apparatus for obtaining backscatter data from a sample, comprising:

an alpha particle emission and detection system configured to obtain backscatter data from the sample, the alpha particle emission and detection system comprising an integrated circuit chip that includes a semiconductor substrate supporting an alpha particle emitter and an alpha particle detector;

the integrated circuit chip having a projection associated therewith;

the projection being configured to be against a surface of the sample or a surface proximate the sample, and to space the alpha particle detector and emitter over the sample to leave a gap between the sample and a portion of the integrated circuit chip over the sample; and

a vacuum system configured to reduce a pressure within the gap to less than atmospheric pressure.

13. The apparatus of claim 12 wherein alpha particle emission and detection system includes shielding between the alpha particle emitter and the alpha particle detector.

14. The apparatus of claim 13 wherein the shielding comprises one or both of platinum and gold.

15. The apparatus of claim 13 wherein the alpha particle emitter, alpha particle detector, and shielding are together comprised by a unit cell;

and wherein the integrated circuit chip comprises an array of the unit cells.

16. The apparatus of claim 13 wherein the alpha particle emitter, alpha particle detector, and shielding are together comprised by a unit cell having a total area along a maximal cross-section of less than about 20 microns².

17. A method of forming an alpha particle emission and detection system, comprising:

forming shielding material over a semiconductor substrate, the shielding material having a receptacle therein;

forming alpha particle emitter material within the receptacle; and

forming at least one alpha particle sensor over the semiconductor substrate, the shielding material being between the at least one sensor and the emitter material.

18. The method of claim 17 wherein the forming the shielding material comprises deposition of one or both of platinum and gold.

19. The method of claim 17 wherein the forming the alpha particle emitter material comprises deposition of one or both of radium and americium.

20. The method of claim 17 wherein the forming the at least one alpha particle sensor comprises formation of a P/N junction.

21. The method of claim 17 wherein the forming the at least one alpha particle sensor comprises formation of a PIN-type device.

22. The method of claim 17 wherein one or more of the alpha particle sensors are formed before the shielding is formed.

23. The method of claim 17 wherein one or more of the alpha particle sensors are formed after the shielding is formed.

24. A method of backscatter analysis, comprising:

placing a sample proximate an alpha particle emission and detection system, the alpha particle emission and detection system comprising at least one integrated circuit chip that includes a semiconductor substrate supporting an alpha particle emitter and an alpha particle sensor;

emitting alpha particles from the alpha particle emitter toward the sample, some of the alpha particles being backscattered by the sample;

detecting the backscattered alpha particles with the alpha particle sensor;

transferring information regarding the backscattered particles from the sensor to a processor; and

processing the information with the processor.

25. The method of claim 24 wherein the sample comprises a semiconductor substrate.

26. The method of claim 24 wherein the placing of the sample comprises movement of the sample into proximity to the alpha particle emission and detection system.

27. The method of claim 24 wherein the placing of the sample comprises movement of the alpha particle emission and detection system into proximity with the sample.

28. The method of claim 24 wherein the placing of the sample comprises placement of the sample beneath an integrated circuit chip comprising an alpha particle emission and detection system to leave a gap between the sample and the integrated circuit chip, and further comprising reducing a pressure within the gap to below atmospheric pressure prior to the emitting and detecting.

29. The method of claim 24 wherein the processor is comprised by integrated circuitry of the integrated circuit chip.

30. The method of claim 24 wherein the processor is separate from the integrated circuit chip.

31. The method of claim 24 wherein alpha particle emission and detection system includes shielding between the alpha particle emitter and the alpha particle sensor.

32. The method of claim 31 wherein the shielding comprises one or both of platinum and gold.