High throughput multi beam detection system and method

• US 7,504,622 B2
• Filed: 03/12/2007
• Issued: 03/17/2009
• Est. Priority Date: 04/03/2006
• Status: Expired due to Fees

• Current Assignee: Applied Materials Israel Limited (Applied Materials Incorporated), Carl Zeiss AG (Carl-Zeiss-Stiftung)
• Original Assignee: Applied Materials Israel Limited (Applied Materials Incorporated)
• Inventors: Elmaliah, Nissim, Elyasaf, Emanuel
• Primary Examiner(s): Wells; Nikita
• Application Number:
  US11/684,965
• Publication Number:
  US 20070228274A1
• Time in Patent Office: 736 Days
• Field of Search: 250/306, 250/307, 385/115, 385/116, 385/88, 385/89, 398/151, 398/156
• US Class Current: 250/306
• CPC Class Codes: G01N 23/2251 using incident electron beams, e.g. scanning electron microscopy [SEM]
• CPC Class Codes: H01J 2237/2446 Position sensitive detectors
• CPC Class Codes: H01J 37/244 Detectors; Associated components or circuits therefor
• CPC Class Codes: H01J 37/29 Reflection microscopes

Abstract

A high-throughput inspection system and method. The system includes: (i) a charged particles to light converter adapted to convert a secondary array of charged particle beams to a first array of light beams; wherein the first array of light beams is characterized by a first ratio of an average first array light beam diameter to an average distance between adjacent first array light beams of the first array; (ii) first optics, positioned between the charged particles to light converter and between inputs of multiple fibers, wherein the first optics is adapted to provide a second array of light beams; wherein each second array light beam corresponds to a first array light beam; wherein the second array of light beams is characterized by a second ratio of an average second array light beam diameter to an average distance between adjacent second array light beams; wherein the second ratio is substantially smaller than the first ratio; (iii) multiple fibers that are adapted to direct second array light beams towards multiple detectors; wherein the inputs of the multiple fibers are positioned in response to an expected spatial disorder of the second array of light beams and to diameters of second array light beams; and (iv) multiple detectors, adapted to detect light from the multiple fibers.

Claims

1. A high-throughput inspection system, comprising:

a charged particles to light converter adapted to convert a secondary array of charged particle beams to a first array of light beams;

wherein the first array of light beams is characterized by a first ratio of an average first array light beam diameter to an average distance between adjacent first array light beams of the first array;

first optics, positioned between the charged particles to light converter and between inputs of multiple fibers, wherein the first optics is adapted to provide a second array of light beams;

wherein each second array light beam corresponds to a first array light beam;

wherein the second array of light beams is characterized by a second ratio of an average second array light beam diameter to an average distance between adjacent second array light beams;

wherein the second ratio is substantially smaller than the first ratio;

multiple fibers that are adapted to direct second array light beams towards multiple detectors;

wherein the inputs of the multiple fibers are positioned in response to an expected spatial disorder of the second array of light beams and to diameters of second array light beams; and

multiple detectors, adapted to detect light from the multiple fibers.

2. The system of claim 1 wherein the first optics comprises a magnifying lens adapted to provide a magnified array of light beams;

wherein the magnifying lens is followed by a first optics micro-lens array.

3. The system according to claim 2 wherein micro-lenses of the first optics micro-lens arrays are positioned in response to an expected spatial disorder of magnified array light beams.

4. The system according to claim 1 further comprising multiple micro-lens arrays, each micro-lens array positioned between a group of fiber bundles and a group of detectors.

5. The system according to claim 1 wherein the multiple detectors are arranged in spaced apart groups and wherein each group of fibers directs a group of light beams towards a group of detectors.

6. The system according to claim 1 wherein the multiple fibers and the first optics are positioned such as to substantially eliminate optical energy losses resulting from a propagation of light from the charged particles to light converter to the multiple sensors.

7. The system according to claim 1 wherein the first ratio is at least five times bigger than the second ratio.

8. The system according to claim 1 wherein the first array of light beams comprises at least one hundred first array light beams and wherein the multiple detectors comprise avalanche photo diodes detectors.

9. The system according to claim 1 wherein the charged particles to light converter is a scintillator that is adapted to reflect light initially directed towards charge particle optics that provided the secondary array of charged particles.

10. The system according to claim 1 wherein the multiple detectors output detection signals via a large number of data paths.

11. A high-throughput inspection method, the method comprises:

converting a secondary array of charged particle beams to a first array of light beams;

wherein the first array of light beams is characterized by a first ratio of an average first array light beam diameter to an average distance between adjacent first array light beams of the first array;

optically converting the first array of light beams to a second array of light beams directed onto multiple inputs of multiple fibers;

wherein each second array light beam corresponds to a first array light beam;

wherein the second array of light beams is characterized by a second ratio of an average second array light beam diameter to an average distance between adjacent second array light beams;

wherein the second ratio is substantially smaller than the first ratio;

directing, by the multiple fibers, the second array light beams towards multiple detectors;

wherein the inputs of the multiple fibers are positioned in response to an expected spatial disorder of the second array of light beams and to diameters of second array light beams; and

detecting light from the multiple fibers by the multiple detectors.

12. The method of claim 11 wherein the converting comprises magnifying the first array of light beams to provide a magnified array of light means and then reducing a size of magnified array light beams without substantially affecting a distance between adjacent light beams.

13. The method according to claim 12 wherein the stage of reducing a size of magnified array light beams without substantially affecting a distance between adjacent light beams comprises passing magnified array light beams through a first optics micro-lens array that comprises micro-lenses that are positioned in response to an expected spatial disorder of the magnified array light beams.

14. The method according to claim 11 further comprising imaging, by multiple micro-lens arrays, an image formed at outputs of the multiple fibers onto multiple detectors.

15. The method according to claim 11 wherein the directing, by the multiple fibers, second array light beams towards multiple detectors, comprises directing by multiple groups of fibers, second array light beams towards multiple spaced apart groups of detectors.

16. The method according to claim 11 wherein the first ratio is at least five times bigger than the second ratio.

17. The method according to claim 11 wherein the detecting comprises detecting at least ten thousand light beams by multiple avalanche photo diodes detectors.

18. The method according to claim 11 wherein the converting a secondary array of charged particle beams to a first array of light beams comprises performing an electro-optical conversion and reflecting light initially directed towards charge particle optics that provided the secondary array of charged particles.

19. The method according to claim 11 wherein the stage of converting a secondary array of charged particle beams involves using a charged particles to light converter;

wherein the stage of optically converting comprises passing the first array light beam through first optics; and

wherein the multiple fibers and the first optic are positioned such as to substantially eliminate optical energy losses resulting from a propagation of light from the charged particles to light converter to the multiple sensors.

20. The method according to claim 11 further comprising outputting multiple detection signals from multiple detectors via a large number of data paths.