CN-122029419-A - System and method for in situ scanning belt positioning

CN122029419ACN 122029419 ACN122029419 ACN 122029419ACN-122029419-A

Abstract

A method for in-situ scan belt positioning includes generating an in-situ scan belt positioning database by selecting a plurality of high contrast alignment targets from pixels to a set of pixels within the design alignment database to the design alignment image. The method includes executing a first runtime scan band of a plurality of runtime dies, wherein each runtime frame associated with the first runtime scan band includes a high contrast alignment target from the in-situ scan band positioning database. The method may include determining one or more offset values for each runtime die based on the plurality of high contrast alignment targets and one or more runtime frames associated with the first runtime scan band. The one or more offset values may include an x offset value and a y offset value for each die. The method may include adjusting an initial stage position based on the determined one or more offset values prior to executing a second runtime scan band.

Inventors

JIANG JUN
QIN WEI
Huang Shuiyao
GOMEZ CINDY
JIN HUAN
CAO KAI
LI XIAOCHUN
PU XIANGFENG

Assignees

科磊股份有限公司

Dates

Publication Date: 20260512
Application Date: 20241117
Priority Date: 20240904

Claims (20)

1. A system, comprising: A controller comprising one or more processors configured to execute a set of program instructions stored in a memory, the set of program instructions configured to cause the one or more processors to: Generating an in-situ scan belt positioning database by selecting a set of a plurality of images of a plurality of high contrast alignment targets from a set of pixels to a design alignment image within the design alignment database; Generating one or more control signals configured to cause an inspection subsystem to execute a first runtime scan band of a plurality of runtime dies on a runtime sample, wherein each runtime frame associated with the first runtime scan band includes at least one high contrast alignment target from the in-situ scan band positioning database, wherein the inspection subsystem executes the first runtime scan band of the plurality of runtime dies on the runtime sample when a sample stage of the inspection subsystem is in an initial stage position; Determining one or more offset values for each runtime die based on the plurality of high contrast alignment targets of the generated in-situ scan band location database and one or more runtime frames associated with the first runtime scan band of the runtime sample, wherein the one or more offset values include at least an x offset value and a y offset value for each die, and One or more control signals are generated that are configured to cause the inspection subsystem to adjust the initial stage position based on the determined one or more offset values prior to executing a second runtime scan band of the plurality of runtime dies on the runtime sample.
2. The system of claim 1, wherein the set of program instructions are further configured to cause the one or more processors to: Performing a pixel-to-design alignment step to align each of a plurality of set dies on a set sample to a target design, and The pixel-to-design alignment database is generated based on the performed pixel-to-design alignment step, the pixel-to-design alignment database including the set of pixel-to-design alignment images for the plurality of alignment targets for each set scan band of the set sample.
3. The system of claim 1, wherein the generating an in situ scan belt positioning database by selecting a set of a plurality of images of a plurality of high contrast alignment targets from a set of pixels to a design alignment image within the design alignment database comprises: Grouping the plurality of alignment targets from the set of pixels into a plurality of bins according to x-position for each scan band, and For each interval, at least one high contrast alignment target is selected from the set of pixels to a design alignment image based on one or more predefined parameters to generate the in situ scan belt positioning database, wherein the one or more predefined parameters include a fraction based on image contrast having a non-repeating pattern and having a higher than a predetermined threshold.
4. The system of claim 1, wherein the set of program instructions are further configured to cause the one or more processors to: Generating a plot of the determined one or more offset values to determine an average offset value; Generating an adjusted stage map based on the determined average offset value, and The adjusted stage map is provided to the sample stage to adjust the initial stage position.
5. The system of claim 1, wherein the set of program instructions are further configured to cause the one or more processors to: One or more defects are identified.
6. The system of claim 1, wherein the inspection subsystem comprises a broadband plasma inspection subsystem.
7. The system of claim 1, wherein the runtime sample comprises a wafer.
8. The system of claim 7, wherein the plurality of runtime dies includes one or more dynamic random access memory dies.
9. A system, comprising: inspection subsystem A controller communicatively coupled to the inspection subsystem, the controller including one or more processors configured to execute a set of program instructions stored in a memory, the set of program instructions configured to cause the one or more processors to: Generating an in-situ scan belt positioning database by selecting a set of a plurality of images of a plurality of high contrast alignment targets from a set of pixels to a design alignment image within the design alignment database; Generating one or more control signals configured to cause the inspection subsystem to execute a first runtime scan band of a plurality of runtime dies on a runtime sample, wherein each runtime frame associated with the first runtime scan band includes at least one high contrast alignment target from the in-situ scan band positioning database, wherein the inspection subsystem executes the first runtime scan band of the plurality of runtime dies on the runtime sample when a sample stage of the inspection subsystem is in an initial stage position; Determining one or more offset values for each runtime die based on the plurality of high contrast alignment targets of the generated in-situ scan band positioning database and one or more runtime frames associated with the first runtime scan band of the sample, wherein the one or more offset values include at least an x offset value and a y offset value for each die, and One or more control signals are generated that are configured to cause the inspection subsystem to adjust the initial stage position based on the determined one or more offset values prior to executing a second runtime scan band of the plurality of runtime dies on the runtime sample.
10. The system of claim 9, wherein the set of program instructions are further configured to cause the one or more processors to: Performing a pixel-to-design alignment step to align each of a plurality of set dies on a set sample to a target design, and The pixel-to-design alignment database is generated based on the performed pixel-to-design alignment step, the pixel-to-design alignment database including the set of pixel-to-design alignment images for the plurality of alignment targets for each set scan band of the set sample.
11. The system of claim 9, wherein the generating an in situ scan belt positioning database by selecting a set of a plurality of images of a plurality of high contrast alignment targets from a set of pixels to a design alignment image within the design alignment database comprises: Grouping the plurality of alignment targets from the set of pixels into a plurality of bins according to x-position for each scan band, and For each interval, at least one high contrast alignment target is selected from the set of pixels to a design alignment image based on one or more predefined parameters to generate the in situ scan belt positioning database, wherein the one or more predefined parameters include a fraction based on image contrast having a non-repeating pattern and having a higher than a predetermined threshold.
12. The system of claim 9, wherein the set of program instructions are further configured to cause the one or more processors to: Generating a plot of the determined one or more offset values to determine an average offset value; Generating an adjusted stage map based on the determined average offset value, and The adjusted stage map is provided to the sample stage to adjust the initial stage position.
13. The system of claim 9, wherein the set of program instructions are further configured to cause the one or more processors to: One or more defects are identified.
14. The system of claim 9, wherein the inspection subsystem comprises a broadband plasma inspection subsystem.
15. The system of claim 9, wherein the runtime sample comprises a wafer.
16. The system of claim 15, wherein the plurality of runtime dies includes one or more dynamic random access memory dies.
17. A method, comprising: Generating an in-situ scan belt positioning database by selecting a set of a plurality of images of a plurality of high contrast alignment targets from a set of pixels to a design alignment image within the design alignment database; Generating one or more control signals configured to cause an inspection subsystem to execute a first runtime scan band of a plurality of runtime dies on a runtime sample, wherein each runtime frame associated with the first runtime scan band includes at least one high contrast alignment target from the in-situ scan band positioning database, wherein the inspection subsystem executes the first runtime scan band of the plurality of runtime dies on the runtime sample when a sample stage of the inspection subsystem is in an initial stage position; Determining one or more offset values for each runtime die based on the plurality of high contrast alignment targets of the generated in-situ scan band positioning database and one or more runtime frames associated with the first runtime scan band of the sample, wherein the one or more offset values include at least an x offset value and a y offset value for each die, and One or more control signals are generated that are configured to cause the inspection subsystem to adjust the initial stage position based on the determined one or more offset values prior to executing a second runtime scan band of the plurality of runtime dies on the runtime sample.
18. The method as recited in claim 17, further comprising: Performing a pixel-to-design alignment step to align each of a plurality of set dies on a set sample to a target design, and The pixel-to-design alignment database is generated based on the performed pixel-to-design alignment step, the pixel-to-design alignment database including the set of pixel-to-design alignment images for the plurality of alignment targets for each set scan band of the set sample.
19. The method of claim 17, wherein the generating an in situ scan belt positioning database by selecting a set of a plurality of images of a plurality of high contrast alignment targets from a set of pixels to a design alignment image within the design alignment database comprises: Grouping the plurality of alignment targets from the set of pixels into a plurality of bins according to x-position for each scan band, and For each interval, at least one high contrast alignment target is selected from the set of pixels to a design alignment image based on one or more predefined parameters to generate the in situ scan belt positioning database, wherein the one or more predefined parameters include a fraction based on image contrast having a non-repeating pattern and having a higher than a predetermined threshold.
20. The method as recited in claim 17, further comprising: Generating a plot of the determined one or more offset values to determine an average offset value; Generating an adjusted stage map based on the determined average offset value, and The adjustment stage map is provided to the sample stage to adjust the initial stage position.

Description

System and method for in situ scanning belt positioning Cross reference to related applications The present application claims U.S. provisional application No. 63/603,119 to 2023, 11, 28 according to 35 U.S. c. ≡119 (e) regulations, the entire contents of which are incorporated herein by reference. Technical Field The present disclosure relates generally to sample testing and, more particularly, to a system and method for in situ scanning belt positioning. Background The need for electronic logic and memory devices with smaller and smaller footprints and features presents a wide range of manufacturing challenges in addition to being manufactured on a desired scale. In the context of semiconductor manufacturing, identifying defects in semiconductor devices is an important step in improving throughput and yield. For example, a defect may be identified by generating a target image of the target die and subtracting a reference image of the reference die from the target image, or vice versa. Thus, differences between images may represent defects. In order to accurately identify defects, the respective pixels in the target image should correspond to the same locations on the die as the respective pixels in the reference image. Thus, the samples should be precisely aligned to ensure correspondence in the target and reference images. Stage position errors, however, present challenges for target-to-reference image alignment. For example, misalignment between the sample and the stage of the inspection subsystem can adversely affect the accuracy of defect identification. Additionally, current run-time alignment techniques only provide relative offset between adjacent dies, however, the first and last dies in the scan band may have large offsets. In addition, the surface metric calculations of current run-time alignment techniques assume that the images have a relatively high contrast, however, with the reduction of design nodes, most images have become low contrast. Accordingly, it is desirable to provide systems and methods for addressing one or more of the above drawbacks. Disclosure of Invention A system for in situ scanning belt positioning is disclosed in accordance with one or more embodiments of the present disclosure. In an embodiment, the system includes a controller including one or more processors configured to execute a set of program instructions stored in a memory. In an embodiment, the set of program instructions are configured to cause the one or more processors to generate an in situ scan belt positioning database by selecting a set of multiple images of a plurality of high contrast alignment targets from a set of pixels to a design alignment image within the design alignment database. In an embodiment, the set of program instructions are configured to cause the one or more processors to generate one or more control signals configured to cause an inspection subsystem to execute a first runtime scan band of a plurality of runtime dies on a runtime sample, wherein each runtime frame associated with the first runtime scan band includes at least one high contrast alignment target from the in-situ scan band positioning database, wherein the inspection subsystem executes the first runtime scan band of the plurality of runtime dies on the runtime sample when a sample stage of the inspection subsystem is in an initial stage position. In an embodiment, the set of program instructions are configured to cause the one or more processors to determine one or more offset values for each runtime die based on the plurality of high contrast alignment targets of the generated in-situ scan band positioning database and one or more runtime frames associated with the first runtime scan band of the sample, wherein the one or more offset values include at least an x offset value and a y offset value for each die. In an embodiment, the set of program instructions are configured to cause the one or more processors to generate one or more control signals configured to cause the inspection subsystem to adjust the initial stage position based on the determined one or more offset values prior to executing a second runtime scan band of the plurality of runtime dies on the runtime sample. A system for in situ scanning belt positioning is disclosed in accordance with one or more embodiments of the present disclosure. In an embodiment, the system includes a verification subsystem. In an embodiment, the system includes a controller communicatively coupled to the inspection subsystem. In an embodiment, the controller includes one or more processors configured to execute a set of program instructions stored in memory. In an embodiment, the set of program instructions are configured to cause the one or more processors to generate an in situ scan belt positioning database by selecting a set of multiple images of a plurality of high contrast alignment targets from a set of pixels to a design alignment image within the design alignment datab