Optical coupling apparatus for a dual column charged particle beam tool for imaging and forming silicide in a localized manner

• US 8,173,948 B2
• Filed: 10/20/2009
• Issued: 05/08/2012
• Est. Priority Date: 10/12/2004
• Status: Expired due to Fees

• Current Assignee: DCG Systems Incorporated (Thermo Fisher Scientific Incorporated)
• Original Assignee: DCG Systems Incorporated (Thermo Fisher Scientific Incorporated)
• Inventors: Tsao, Chun-Cheng
• Primary Examiner(s): Sohn, Seung C
• Application Number:
  US12/582,553
• Publication Number:
  US 20100038555A1
• Time in Patent Office: 931 Days
• Field of Search: 250/208.3, 250/396.R, 356/369, 356/493, 356/507
• US Class Current: 250/208.3
• CPC Class Codes: H01J 2237/2482 Optical means
• CPC Class Codes: H01J 2237/31749 Focused ion beam
• CPC Class Codes: H01J 37/228 whereby illumination and light collection take place in the same area of the discharge
• CPC Class Codes: H01J 37/3056 for microworking, e.g. etching of gratings, trimming of electrical components trimming of resistors H01C17/22
• CPC Class Codes: H01L 21/76892 modifying the pattern
• CPC Class Codes: H01L 21/76898 formed through a semiconductor substrate

Abstract

An optical coupling apparatus for a dual column charged particle beam tool allowing both optical imaging of an area of an integrated circuit, as well as localized heating of the integrated circuit to form silicide. In one embodiment, optical paths from a whitelight source and a laser source are coupled together by way of first and second beam splitters so that a single optical port of the dual column tool may be utilized for both imaging and heating. In another embodiment, a single laser source is employed to provide both illumination for standard microscopy-type imaging, as well as localized heating. In a third embodiment, a single laser source provides heating along with localized illumination for confocal scanning microscopy-type imaging.

Claims

1. A charged particle beam apparatus having dual optical illumination for operating on an integrated circuit (IC), comprising:

a particle beam column having a particle beam path and an optical path;

a laser source producing a laser beam;

a light source producing a light beam;

an optical coupling assembly coupling the laser beam and the light beam into the column to thereby follow the optical path;

an image sensor receiving reflections from the IC via the optical path.

2. The apparatus of claim 1, wherein the light source comprises a whitelight source.

3. The apparatus of claim 2, further comprising optical elements to direct the light beam to generate flood illumination.

4. The apparatus of claim 2, further comprising a filter positioned in a path of the light beam.

5. The apparatus of claim 1, wherein the particle beam column comprises a single optical port and wherein the optical coupling assembly couples the laser beam and the light beam through the single optical port to thereby have the laser beam and light beam to follow substantially the same path within the column.

6. The apparatus of claim 1, wherein the optical path is configured to direct the laser beam onto the IC so as to apply heat to a localized area of the IC.

7. The apparatus of claim 1, further comprising a collimation lens provided in a path of the laser beam so as to control laser spot size.

8. The apparatus of claim 1, wherein the laser source comprises a pulsed laser source.

9. The apparatus of claim 1, wherein the light source comprises a second laser source.

10. The apparatus of claim 9, further comprising a configurable laser light converter configured for transforming laser illumination into either an illumination beam or a heating beam.

11. The apparatus of claim 10, wherein the configurable laser light converter comprises a condenser lens, a field lens and a collimating lens.

12. The apparatus of claim 11, wherein the collimating lens is translatable in and out of an optical path defined within the configurable laser light converter.

13. The apparatus of claim 12, wherein the condenser lens and the field lens are translatable in and out of the optical path defined within the configurable laser light converter.

14. The apparatus of claim 10, further comprising an optical switch for selectively coupling light from the laser source and the second laser source onto the configurable laser light converter.

15. The apparatus of claim 11, further comprising an objective lens and wherein the image sensor is coupled to the optical coupling assembly.

16. The apparatus of claim 10, the configurable laser light converter is structured to assume a first configuration wherein entering laser light is converted to a first light beam comprising a first width, and a second configuration wherein entering laser light is converted to a second light beam comprising a second width narrower than the first width.

17. The apparatus of claim 12, the first configuration of configurable laser light converter comprising:

a condenser lens optically coupled with the laser source;

an aperture stop optically coupled with the condenser lens;

a field stop optically coupled with the aperture stop; and

a field lens optically coupled with the field stop.

18. A charged particle beam apparatus having dual optical illumination for operating on an integrated circuit (IC), comprising:

a particle beam column having a particle beam path and an optical path;

a laser source producing a laser beam;

first optics conditioning the laser beam so as to apply heat to a localized area of the IC;

a whitelight source producing a light beam;

second optics conditioning the light beam to illuminate an area of the IC;

an optical coupling assembly coupling the laser beam and the light beam into the column to thereby follow the optical path;

an image sensor receiving reflections of the light beam from the IC via the optical path.

19. The apparatus of claim 18, further comprising a selectable bandpass filter positioned in a path of the light beam.

20. The apparatus of claim 19, further comprising a fiber optics coupled to the whitelight source, an aperture stop at the image plane of the fiber optics, an a field stop positioned at the conjugate of the IC'"'"'s image plane.