Charged particle multi-beam inspection system and method of operating the same

Patent metadata

Field	Value
Publication number	US-9263233-B2
Application number	US-201414499228-A
Country	US
Kind code	B2
Filing date	Sep 28, 2014
Priority date	Sep 29, 2013
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

Abstract

A charged particle multi-beam inspection system comprises a beam generator directing a plurality of primary charged particle beams onto an object to produce an array of beam spots; an array of a first number of detection elements generating detection signals upon incidence of electrons; imaging optics imaging the array of beam spots onto the array of detection elements; wherein the beam generator includes a multi-aperture plate having an array of a second number of apertures greater than the first number; wherein the beam generator includes a selector having plural different states, wherein, in each of the plural different states, the apertures of a different group of apertures are each traversed by one primary charged particle beam, wherein a number of the apertures of the different group of apertures is equal to the first number.

First claim

The invention claimed is:

1. A charged particle multi-beam inspection system, comprising:
a beam generator configured to generate a plurality of primary charged particle beams and to direct the plurality of primary charged particle beams onto an object plane such that an array of beam spots is produced on the object plane;
an array of a first number of detection elements configured to generate detection signals upon incidence of electrons on the detection elements;
charged particle imaging optics configured to image the array of beam spots onto the array of detection elements such that electrons generated by the primary charged particle beams at each beam spot are directed onto a corresponding detection element;
wherein the beam generator includes a multi-aperture plate having an array of a second number of apertures;
wherein the second number is greater than the first number;
wherein the beam generator is configured such that the apertures of a group of apertures are each traversed by one primary charged particle beam producing a beam spot which is imaged onto one of the detection elements, wherein a number of the apertures of the group of apertures is equal to the first number;
wherein the beam generator includes a selector having plural different states, wherein, in each of the plural different states, the apertures of a different group of apertures are each traversed by one primary charged particle beam producing a beam spot which is imaged onto one of the detection elements, wherein a number of the apertures of the different group of apertures is equal to the first number.

2. The charged particle multi-beam inspection system according to claim 1 , wherein the selector comprises a first actuator configured to laterally displace the multi-aperture plate between plural different positions such that, in each of the plural different states, the multi-aperture plate is in a different position.

3. The charged particle multi-beam inspection system according to claim 1 , wherein the selector comprises a charged particle beam deflector and a controller configured to energize the charged particle beam deflector and to adjust plural different deflection amounts provided by the charged particle beam deflector such that, in each of the plural different states, a different deflection amount is adjusted.

4. The charged particle multi-beam inspection system according to claim 3 , wherein the selector comprises a plate having an aperture traversed by particles of all beams directed onto the object, and a second actuator configured to laterally displace the plate between plural different positions.

5. A method of operating the charged particle multi-beam inspection system of claim 1 , the method comprising:
setting the selector to a first state in which the apertures of a first group of a number of apertures, the number of apertures equal to the first number, are each traversed by one primary charged particle beam producing a beam spot which is imaged onto one of the detection element;
determining that at least one aperture of the apertures of the first group of apertures has a deficiency; and
setting the selector to a second state in which the apertures of a second group of the second number of apertures are each traversed by one primary charged particle beam producing a beam spot which is imaged onto one of the detection element, wherein the first group of apertures is different from the second group of apertures.

Assignees

• Zeiss Carl Microscopy Gmbh
• Applied Materials Israel Ltd

Inventors

• Zeidler Dirk
• Knippelmeyer Rainer
• Kemen Thomas
• Muetzel Mario
• Schubert Stefan
• Elmaliah Nissim
• Rogers Steven

Classifications

• H01J2237/0453

  multiple apertures · CPC title

• H01J2237/24592

  Inspection and quality control of devices · CPC title

• H01J37/28 Primary

  with scanning beams {(H01J37/268, H01J37/292, H01J37/2955 take precedence)} · CPC title