US-20260128254-A1 - ELECTRON-OPTICAL MODULE

US20260128254A1US 20260128254 A1US20260128254 A1US 20260128254A1US-20260128254-A1

Abstract

A charged particle-optical module ( 41 ) for directing charged particles along a path towards a sample location, the charged particle-optical module comprises: a plurality of planar elements or electrodes ( 61 - 64 ) arranged across the path and configured to operate on the charged particles; a thermal conditioning channel 80 spaced from the planar elements in a direction through the plurality of elements; and a thermally conductive plate ( 61 - 64; 240; 75 ) connected to the thermal conditioning channel for transferring heat towards the thermal conditioning channel; wherein the thermally conductive plate extends between the planar elements and the thermal conditioning channel in a direction parallel to one or more of the planar elements.

Inventors

Johannes Cornelis Jacobus De Langen
Johan Joost Koning
Laura DEL TIN
Olivier Jacob DOESBURG
Gomaar ZIJL

Assignees

ASML NETHERLANDS B.V.

Dates

Publication Date: 20260507
Application Date: 20230918
Priority Date: 20221007

Claims (20)

1 . A charged particle-optical module for directing charged particles along a beam path towards a sample location, the charged particle-optical module comprising: a plurality of planar elements arranged across the beam path and configured to operate on the charged particles; a thermal conditioning channel spaced from the planar elements in a direction through the plurality of elements; and a thermally conductive plate connected to the thermal conditioning channel for transferring heat towards the thermal conditioning channel; wherein the thermally conductive plate extends between the planar elements and the thermal conditioning channel in a direction parallel to one or more of the planar elements.
2 . The charged particle-optical module of claim 1 , further comprising a material electrically isolating the planar elements from the thermal conditioning channel.
3 . The charged particle-optical module of claim 2 , wherein the material surrounds one or more of the planar elements.
4 . The charged particle-optical module of claim 2 , or wherein the material continuously fills a volume between one or more planar elements and the thermal conditioning channel, the volume has a surface that is defined by at least one of: a. a portion of a surface of the thermally conductive plate parallel to one or more of the planar elements; b. a surface of the channel; c. an outer surface of one or more planar elements; or d. one or more spacers i. between adjoining planar elements; or ii. between an individual planar element and the thermally conductive plate.
5 . The charged particle-optical module of claim 1 , wherein a distance between the planar elements and the thermal conditioning channel is less than a distance between an edge of the planar elements and a centre of the beam path and/or wherein a distance between the planar elements and the thermal conditioning channel when viewed in a direction parallel to the beam path is less than a width of the thermal conditioning channel.
6 . The charged particle-optical module of claim 1 , wherein a surface of the thermal conditioning channel facing a direction parallel to the beam path is covered with an electrical insulator and/or wherein a surface of the thermal conditioning channel facing away from the beam path is covered with an electrical insulator.
7 . The charged particle-optical module of claim 1 , wherein the thermally conductive plate is monolithic, comprising a planar element and/or wherein the thermally conductive plate is, or is connected to, a planar element.
8 . The charged particle-optical module of claim 18 , wherein the detector is secured to, the thermally conductive plate.
9 . The charged particle-optical module of claim 1 , wherein the thermally conductive plate is, or is connected to, a planar element comprising: an array of apertures for passage of one or more beam paths.
10 . The charged particle-optical module of claim 9 , wherein said planar element comprises plurality of electrodes configured to apply aberration corrections to one or more of the beam paths, the electrodes being arranged relative to respective apertures of the array of apertures.
11 . The charged particle-optical module of claim 1 , wherein at least one of the planar elements is a beam limiting aperture array configured to shape one or more beams of charged particles.
12 . The charged particle-optical module of claim 1 , further comprising electronic circuitry, in a circuitry layer, in the thermally conductive plate and/or detector.
13 . The charged particle-optical module of claim 1 , further comprising a plurality of thermal conditioning channels extending along different sides of the planar elements.
14 . The charged particle-optical module of claim 1 , further comprising one or more spacer elements between two adjoining planar elements of the plurality of planar elements, an individual spacer element configured to support and/or electrically isolate the adjoining planar elements.
15 . A charged particle-optical device for directing charged particles onto a sample location, the charged particle-optical device comprising the charged particle-optical module of claim 1 .
16 . The charged particle-optical module of claim 1 , further comprising a further thermally conductive plate, the further conductive plate extending between the planar elements and the thermal conditioning channel.
17 . The charged particle-optical module of claim 7 , wherein the planar element is a detector for detecting signal particles from the sample location.
18 . The charged particle-optical module of claim 17 , wherein the detector has a thickness in a direction parallel to the beam path greater than or substantially equal to a thickness of one or more of the planar elements.
19 . The charged particle-optical device of claim 15 , wherein the planar elements comprise a beam stop array, downbeam of another planar element that is a deflector array, wherein the deflector array may be comprised in the same charged particle-optical module as the beam stop array, the beam stop array comprising an array of apertures for passage of beam paths, wherein individual deflectors of the deflector array are configured to controllably operate on the individual beams or beam groups to be blocked by the beam stop array or to be directed through an individual aperture.
20 . A method for moderating a temperature of one or more components of a charged particle-optical module for use in a charged particle-optical apparatus to direct charged particles along a beam path towards a sample location, the charged particle-optical module comprising a plurality of planar elements configured to operate on charged particles, a thermal conditioning channel spaced away from the plurality of planar elements, and a thermally conductive plate extending between and in thermal contact with the plurality of planar elements and the thermal conditioning channel, the method comprising: operating the charged particle-optical apparatus to project charged particles to a sample location; flowing thermal conditioning fluid through the thermal conditioning channel; and transferring heat towards the thermal conditioning channel through the thermally conductive plate.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority of EP application 22200380.8 which was filed on 7 Oct. 2022 and which is incorporated herein in its entirety by reference. FIELD The embodiments provided herein generally relate to a charged particle-optical module, a charged particle-optical device, a charged particle-optical apparatus and a method for moderating a temperature of one or more components of a charged particle-optical module. BACKGROUND When manufacturing semiconductor integrated circuit (IC) chips, undesired pattern defects may occur on a substrate (e.g. wafer) or a mask during the fabrication processes, thereby reducing the yield. Defects may occur as a consequence of, for example, optical effects and incidental particles or other processing step such as etching, deposition of chemical mechanical polishing. Monitoring the extent of the undesired pattern defects is therefore an important process in the manufacture of IC chips. More generally, the inspection and/or measurement of a surface of a substrate, or other object/material, is an important process during and/or after its manufacture. Pattern inspection tools with a charged particle beam have been used to inspect objects, for example to detect pattern defects. These tools typically use electron microscopy techniques, such as a scanning electron microscope (SEM). In a SEM, a primary electron beam of electrons at a relatively high energy is targeted with a final deceleration step in order to land on a target at a relatively low landing energy. The beam of electrons is focused as a probing spot on the target. The interactions between the material structure at the probing spot and the landing electrons from the beam of electrons cause electrons to be emitted from the surface, such as secondary electrons, backscattered electrons or Auger electrons, which together may be referred as signal electrons or more generally signal particles. The generated secondary electrons may be emitted from the material structure of the target. By scanning the primary electron beam as the probing spot over the target surface, secondary electrons can be emitted across the surface of the target. By collecting these emitted secondary electrons from the target surface, a pattern inspection tool (or apparatus) may obtain an image-like signal representing characteristics of the material structure of the surface of the target. In such inspection the collected secondary electrons are detected by a detector within the apparatus. The detector generates a signal in response to the incidental particle. As an area of the sample is inspected, the signals comprise data which is processed to generate the inspection image corresponding to the inspected area of the sample. The image may comprise pixels. Each pixel may correspond to a portion of the inspected area. Typically electron beam inspection apparatus has a single beam and may be referred to as a Single Beam SEM. There have been attempts to introduce a multi-electron beam inspection in a apparatus (or a ‘multi-beam tool’) which may be referred to as Multi Beam SEM (MBSEM). Another application for an electron-optical device (or column) is lithography. The charged particle beam reacts with a resist layer on the surface of a substrate. A desired pattern in the resist can be created by controlling the locations on the resist layer that the charged particle beam is directed towards. An electron-optical device may be an apparatus for generating, illuminating, projecting and/or detecting one or more beams of charged particles. The path of the beam of charged particles is controlled by electromagnetic fields (i.e. electrostatic fields and magnetic fields). Stray electromagnetic fields can undesirably divert the beam. During use of some electron-optical devices, the energy from the electron beam(s) heats the electron-optical elements. It can be difficult to moderate the temperature of components of the electron-optical device. SUMMARY The present invention provides a suitable architecture to enable improved control of temperatures within the electron-optical apparatus. According to a first aspect of the invention, there is provided a charged particle-optical module for directing charged particles along a beam path towards a sample location, the charged particle-optical module comprising: a plurality of planar elements arranged across the beam path and configured to operate on the charged particles; a thermal conditioning channel spaced from the planar elements in a direction through the plurality of elements; and a thermally conductive plate connected to the thermal conditioning channel for transferring heat towards the thermal conditioning channel; wherein the thermally conductive plate extends between the planar elements and the thermal conditioning channel in a direction parallel to one or more of the planar elements. According to a second aspect of the invention, there is provided a method for moderating a