KR-20260064729-A - MASSIVE OVERLAY METROLOGY SAMPLING WITH MULTIPLE MEASUREMENT COLUMNS

Abstract

A multi-column measurement tool may include two or more measurement columns distributed along the column direction, and the two or more measurement columns simultaneously probe two or more measurement regions on a sample containing measurement targets. A measurement column includes an illumination subsystem for directing illumination toward the sample, a collection subsystem including a collection lens for collecting measurement signals from the sample and directing them toward one or more detectors, and a column positioning subsystem for adjusting the position of the collection lens. The measurement region of the measurement column may be defined by the field of view of the collection lens and the range of the positioning system in the lateral plane. The tool may further include a sample positioning subsystem for scanning the sample along a scan path different from the column direction to position measurement targets within the measurement regions of the measurement columns for measurements.

Inventors

• 매드센 조나단
• 쉬체그로프 안드레이 브이.
• 마나쎈 암논
• 힐 앤드류 브이.
• 시몬 요씨
• 라레도 길라드
• 우지엘 요람

Assignees

• 케이엘에이 코포레이션

Dates

Publication Date

20260507

Application Date

20211028

Priority Date

20210324

Claims (20)

1. In multi-column measurement tools, Two or more measurement columns distributed along the column direction—the two or more measurement columns are configured to simultaneously probe two or more measurement regions on a sample including a plurality of measurement targets, and a specific measurement column among the two or more measurement columns is, A lighting subsystem configured to direct light from at least one of one or more lighting sources toward the sample; A collection subsystem comprising a collection lens configured to collect measurement signals from the above sample and to direct the measurement signals to one or more detectors; and Includes a column positioning subsystem configured to adjust the position of the collecting lens within a lateral plane parallel to the sample plane for measurement, wherein the measurement area of the specific measurement column is defined by the range of the positioning system within the lateral plane and the field of view of the collecting lens - ; and A sample positioning subsystem configured to scan the sample along a scan path different from the column direction described above. A multi-column measurement tool comprising, wherein the scan path positions measurement targets among the plurality of measurement targets within the measurement regions of the two or more measurement columns for measurements, and the column positioning subsystems of the two or more measurement columns position the collection lenses of the two or more measurement columns to align the measurement targets within the measurement regions along the scan path for measurements.
2. A multi-column measuring tool according to claim 1, wherein the column positioning subsystem of at least one of the two or more measuring columns is also configured to adjust the position of an associated collecting lens along an axial direction perpendicular to the lateral plane.
3. In paragraph 2, the column positioning subsystem also adjusts the position of the associated collection lens along the axial direction to the desired measurement planes of the measurement targets for the measurements, a multi-column measurement tool.
4. A multi-column measurement tool according to claim 1, wherein at least one of the two or more measurement columns collects measurement signals from two or more measurement planes and directs the measurement signals from the two or more measurement planes to at least one of the one or more detectors.
5. A multi-column measuring tool according to claim 1, wherein the sample positioning subsystem is also configured to adjust the position of the sample along an axial direction perpendicular to the lateral plane.
6. A multi-column measuring tool according to claim 1, wherein the sample positioning subsystem includes a rotation stage for rotating the sample.
7. A multi-column measuring tool according to claim 1, wherein at least one of the one or more detectors comprises a fixed detector located outside the two or more measuring columns.
8. A multi-column measurement tool according to claim 7, wherein the measurement signals provided by at least two of the two or more measurement columns are multiplexed by one or more parameters.
9. In paragraph 8, the above one or more parameters are, A multi-column measuring tool comprising at least one of polarization, wavelength, or time.
10. A multi-column measurement tool according to claim 8, wherein the fixed detector provides separate detector data associated with the multiplexed measurement signals from at least two of the two or more measurement columns.
11. In paragraph 8, A multi-column measurement tool further comprising a detection demultiplexer configured to receive the multiplexed measurement signals from at least two of the two or more measurement columns and to generate two or more demultiplexed measurement signals, wherein the detection demultiplexer also distributes the two or more demultiplexed detection signals to the fixed detector.
12. A multi-column measuring tool according to claim 8, wherein the illumination received by at least two of the two or more measuring columns is multiplexed by the one or more parameters.
13. A multi-column measuring tool according to claim 7, wherein at least one of the two or more measuring columns directs the measurement signals through one or more optical fibers.
14. A multi-column measuring tool according to claim 1, wherein at least one of the one or more detectors comprises movable detectors positioned on at least one of the two or more measuring columns.
15. A multi-column measuring tool according to claim 1, wherein at least one of the one or more lighting sources comprises a fixed lighting source located outside the two or more measuring columns.
16. A multi-column measuring tool according to claim 15, wherein at least two of the two or more measuring columns receive illumination from the fixed light source.
17. A multi-column measuring tool according to claim 15, wherein at least one of the two or more measuring columns receives illumination from the fixed light source through one or more optical fibers.
18. A multi-column measuring tool according to claim 1, wherein at least one of the one or more lighting sources comprises movable lighting sources located on at least one of the two or more measuring columns.
19. A multi-column measuring tool according to claim 1, wherein at least one of the one or more light sources comprises an electromagnetic light source.
20. A multi-column measuring tool according to claim 1, wherein at least one of the one or more light sources comprises a particle beam light source.

Description

Massive Overlay Metrology Sampling with Multiple Measurement Columns [Cross-reference to related applications] This application claims the benefit of 35 U.S.C. § 119(e) of U.S. Provisional Application No. 63/116,163, filed on November 20, 2020, under the title “MASSIVE OVERLAY METROLOGY SAMPLING FOR SEMICONDUCTORS WAFER LITHOGRAPHY AND PATTERNING PROCESS CONTROL BY MULTI OPTICAL COLUMNS AND SIGNAL MULTIPLEXING,” naming John Madsen, Andrei Szczegrov, Jossi Simon, Andy Hill, Yoram Uziel, and Amnon Manasen, the entirety of which is incorporated herein by reference. [Technology Field] The present disclosure generally relates to optical measurement, and more specifically, to optical measurement using a plurality of measurement columns for high throughput sampling. The demands for reduced feature size and increased feature density are, correspondingly, leading to increased demands for accurate and efficient measurement. One approach to increasing the efficiency and throughput of a metrology system is to utilize optical metrology tools and dedicated metrology targets suitable for measurements using such tools. For example, optical metrology can generally, but is not limited to, provide measurements with relatively higher throughput than particle-based metrology systems, such as electron beam (e-beam) metrology systems, although accuracy may be limited by the wavelength of light in the system. Nevertheless, using dedicated overlay targets, as well as sampling a larger number of samples distributed across the sample, can provide sufficient accuracy using optical techniques that achieve a total throughput exceeding that of particle-based systems. Next-generation semiconductor devices may require sub-nanometer overlay accuracy requirements related to the relative registration of successive layers in the semiconductor manufacturing process. As overlay tolerances become stricter, the number of overlay targets required to provide the necessary level of control continues to increase. Therefore, it is desirable to provide systems and methods for accurate and efficient measurement. A multi-column measurement tool is disclosed according to one or more exemplary embodiments of the present disclosure. In one exemplary embodiment, the tool comprises two or more measurement columns distributed along the column direction, and the two or more measurement columns simultaneously probe two or more measurement regions on a sample comprising a plurality of measurement targets. In another exemplary embodiment, a particular measurement column among the two or more measurement columns comprises an illumination subsystem for directing illumination from at least one of one or more illumination sources toward the sample, a collection subsystem comprising a collection lens for collecting measurement signals from the sample and directing the measurement signals toward one or more detectors, and a column positioning subsystem for adjusting the position of the collection lens in a lateral plane parallel to the sample plane for measurement. In another exemplary embodiment, the measurement region of a particular measurement column is defined by the field of view of the collection lens and the range of the positioning system in the lateral plane. In another exemplary embodiment, the tool includes a sample positioning subsystem for scanning a sample along a scan path different from the column direction, the scan path positioning measurement targets among a plurality of measurement targets within the measurement areas of two or more measurement columns for measurements. In another exemplary embodiment, the column positioning subsystems of two or more measurement columns position the collection lenses of two or more measurement columns so that, for measurements, measurement targets within the measurement areas along the scan path are aligned within the fields of view of the collection lenses. A multi-column measurement tool is disclosed according to one or more exemplary embodiments of the present disclosure. In one exemplary embodiment, the tool comprises two or more measurement columns distributed in a two-dimensional pattern, the two or more measurement columns simultaneously probe two or more measurement regions on a sample comprising a plurality of measurement targets, and the measurement regions of the two or more measurement columns are distributed to cover one or more selected regions of a sample comprising at least some of the plurality of measurement targets. A particular measurement column among the two or more measurement columns may comprise an illumination subsystem for directing illumination from at least one of one or more illumination sources toward the sample, a collection subsystem comprising a collection lens for collecting measurement signals from the sample and directing the measurement signals toward one or more detectors, and a column positioning subsystem for adjusting the position of the collection lens in a lateral plane par