Process monitoring

Patent metadata

Field	Value
Publication number	US-11022565-B2
Application number	US-201916405920-A
Country	US
Kind code	B2
Filing date	May 7, 2019
Priority date	May 7, 2019
Publication date	Jun 1, 2021
Grant date	Jun 1, 2021

Abstract

A method for determining a defect material element, the method includes (a) acquiring, by a charged particle beam system and by applying a spectroscopy process, an electromagnetic emission spectrum of a part of a defect; (b) acquiring, by the charged particle beam system, a backscattered electron (BSE) image of an area that includes the defect; and (c) determining a defect material element. The determining of the defect material element includes: determining whether an ambiguity exists in the electromagnetic emission spectrum, and resolving the ambiguity based on the BSE image, when it is determined that the ambiguity exists.

First claim

What is claimed is:

1. A method for determining a defect material element of a defect, the method comprising:
acquiring, by a charged particle beam system and by applying a spectroscopy process, an electromagnetic emission spectrum of a part of the defect;
acquiring, by the charged particle beam system, a backscattered electron (BSE) image of an area that comprises the defect; and
determining the defect material element by determining whether an ambiguity exists in the electromagnetic emission spectrum and resolving the ambiguity based on the BSE image in response to determining that the ambiguity exists;
wherein acquiring the BSE image comprises illuminating the area with electrons having an incident energy and generating the BSE image substantially only from BSE electrons having an energy above an energy threshold.

2. The method according to claim 1 wherein resolving the ambiguity comprises selecting the defect material element out of potential material elements that exhibit peaks that are spaced apart from each other by an energy difference that is lower than a resolution of the spectroscopy process.

3. The method according to claim 2 wherein the potential material elements comprise an organic material element and a heavier material element.

4. The method according to claim 1 wherein resolving the ambiguity comprises selecting the defect material element based on an intensity of one or more BSE image pixels of the defect.

5. The method according to claim 1 wherein the area comprises the defect and a background material that surrounds the defect, and wherein the method comprises determining a background material element of the background material.

6. The method according to claim 5 wherein determining the defect material element is based on the background material element.

7. The method according to claim 6 wherein the background material element has an atomic weight that belongs to a background atomic weight class, and wherein determining the defect material element comprises determining an atomic weight class of the defect material element based on a relationship between (a) an intensity parameter of one or more BSE image pixels of the background material, and (b) the intensity parameter of one or more BSE image pixels of the defect.

8. The method according to claim 7 comprising classifying the atomic weight class of the defect material element to a class out of (a) lighter than background material class, (b) the background atomic weight class, and (d) at least one class of heavier than background material class.

9. A method for determining a defect material element of a defect, the method comprising:
acquiring, by a charged particle beam system and by applying a spectroscopy process, an electromagnetic emission spectrum of a part of the defect;
acquiring, by the charged particle beam system, a backscattered electron (BSE) image of an area that comprises the defect; and
determining the defect material element by determining whether an ambiguity exists in the electromagnetic emission spectrum and resolving the ambiguity based on the BSE image in response to determining that the ambiguity exists;
wherein the area comprises the defect and a background material that surrounds the defect, and wherein the method comprises determining a background material element of the background material; and
wherein the background material is silicon, wherein the determining of the defect material element comprises classifying the defect material element to a class out of (a) second period of the periodic table of elements, (b) third period of the periodic table of elements, (c) fourth period of the periodic table of elements, and (d) sixth period of the periodic table of elements.

10. The method according to claim 1 comprising determining whether the ambiguity exists in the electromagnetic emission spectrum, and acquiring the BSE image in response to the ambiguity existing in the electromagnetic emission spectrum.

11. A method for determining a defect material element of a defect, the method comprising:
acquiring, by a charged particle beam system and by applying a spectroscopy process, an electromagnetic emission spectrum of a part of the defect;
acquiring, by the charged particle beam system, a backscattered electron (BSE) image of an area that comprises the defect; and
determining the defect material element by determining whether an ambiguity exists in the electromagnetic emission spectrum and resolving the ambiguity based on the BSE image in response to determining that the ambiguity exists;
wherein acquiring the BSE image comprises rejecting BSE electrons that originate from locations that are positioned below a certain depth from a surface of the area.

12. A non-transitory computer readable medium comprising instructions, which when executed by a processor, cause the processor to perform operations comprising:
acquiring an electromagnetic emission spectrum of a part of a defect;
acquiring a backscattered electron (BSE) image of an area that comprises the defect; and
determining a defect material element by determining whether an ambiguity exists in the electromagnetic emission spectrum and resolving the ambiguity based on the BSE image in response to determining that the ambiguity exists;
wherein acquiring the BSE image comprises illuminating the area with electrons having an incident energy and generating the BSE image substantially only from BSE electrons having an energy above an energy threshold.

13. A charged particle beam system that comprises charged particle optics and a processor, wherein the processor is configured to:
acquire, by applying a spectroscopy process, an electromagnetic emission spectrum of a part of a defect;
acquire a backscattered electron (BSE) image of an area that comprises the defect; and
determine a defect material element by determining whether an ambiguity exists in the electromagnetic emission spectrum and resolving the ambiguity based on the BSE image in response to determining that the ambiguity exists;
wherein acquiring the BSE image comprises illuminating the area with electrons having an incident energy and generating the BSE image substantially only from BSE electrons having an energy above an energy threshold.

Assignees

• Applied Materials Israel Ltd

Inventors

• Shemesh Dror
• Bullock Eugene T
• BOEHM Adi
• Singh Gurjeet

Classifications

• G01N2223/053

  back scatter · CPC title

• G01N2223/079

  incident electron beam and measuring excited X-rays · CPC title

• G01N21/8851

  Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges (G01N21/8806 and G01N21/93 - G01N21/95692 take precedence; optical measurement of dimensions G01B11/00; optical scanning G02B26/10; image transformation G06T3/00; computerised image enhancement G06T5/00; image processing per se for flaw detection G06T7/0002) · CPC title

• G01N2021/8854

  Grading and classifying of flaws · CPC title

• G01N2223/418

  electron microscope · CPC title