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EP-4122007-B1 - DETERMINING METROLOGY-LIKE INFORMATION FOR A SPECIMEN USING AN INSPECTION TOOL

EP4122007B1EP 4122007 B1EP4122007 B1EP 4122007B1EP-4122007-B1

Inventors

  • LI, SHIFANG

Dates

Publication Date
20260506
Application Date
20210309

Claims (15)

  1. A system configured for determining metrology-like information for a specimen (14), comprising: one or more output acquisition subsystems (10) configured to generate output responsive to energy detected from a specimen, wherein the one or more output acquisition subsystems comprise an inspection subsystem configured to generate at least a portion of the output responsive to the energy detected from the specimen while the energy is scanned over the specimen; and one or more computer subsystems (102, 36) configured for: determining first process information for one or more first features formed in one or more first areas on the specimen from the output; and determining second process information for one or more second features formed in one or more second areas on the specimen from the output and at least a portion of the first process information, wherein at least a portion of the second process information is a different type of information than the first process information, wherein at least a portion of a design for the one or more second features is different than a design for the one or more first features, and wherein the one or more first areas and the one or more second areas are mutually exclusive on the specimen.
  2. The system of claim 1, wherein the output used to determine the first process information comprises only the output generated by the inspection subsystem, and wherein the output used to determine the second process information comprises only the output generated by the inspection subsystem; or wherein the output used to determine the first process information comprises only the output generated by the inspection subsystem, and wherein the output used to determine the second process information comprises only the output generated by the inspection subsystem; and wherein the output used to determine the first and second process information is generated in the same scan of the specimen.
  3. The system of claim 1, wherein the one or more output acquisition subsystems further comprise a metrology tool configured to generate at least another portion of the output by performing measurements at measurement points on the specimen, wherein the output used to determine the first process information comprises only the at least another portion of the output, and wherein the output used to determine the second process information comprises the at least the portion of the output.
  4. The system of claim 1, wherein the output used to determine the first process information is not generated until the one or more second features are formed on the specimen.
  5. The system of claim 1, wherein the second process information comprises a setting of a process performed on the specimen; or wherein the second process information comprises a characteristic of the one or more second features.
  6. The system of claim 1, wherein the one or more first areas are selected to capture specimen level variations in the first process information; or wherein the one or more first areas are selected to capture die level variations in the first process information.
  7. The system of claim 1, wherein the one or more computer subsystems are further configured for detecting defects on the specimen by modifying the at least the portion of the output generated by inspection subsystem with one or more of the first and second process information thereby generating modified output and applying a defect detection method to the modified output; or wherein the one or more computer subsystems are further configured for determining one or more of the first and second process information using an empirically determined relationship; or wherein the one or more computer subsystems are further configured for determining one or more of the first and second process information using a rigorous model.
  8. The system of claim 1, wherein determining the second process information comprises interpolation of the first process information from one or more locations of the one or more first areas to one or more locations of the one or more second areas; or wherein determining the second process information comprises extrapolation of the first process information from one or more locations of the one or more first areas to one or more locations of the one or more second areas.
  9. The system of claim 1, wherein the one or more computer subsystems are further configured for selecting the first process information, the one or more first features, the one or more first areas, the one or more second features, and the one or more second areas based on information for a design for the specimen and one or more processes performed on the specimen; or wherein the one or more computer subsystems are further configured for determining one or more methods used for determining the first and second process information based on information for a design for the specimen and one or more processes performed on the specimen.
  10. The system of claim 1, wherein determining the first process information comprises applying a first method to the output, wherein determining the second process information comprises applying a second method to the output and the at least the portion of the first process information, and wherein the first and second methods are different.
  11. The system of claim 1, wherein the one or more computer subsystems are further configured for performing a single method for determining the first and second process information; or wherein the one or more computer subsystems are further configured for performing a single method for determining the first and second process information; and wherein input to the single method is the output generated for the specimen by the one or more output acquisition subsystems, and wherein output of the single method is the second process information.
  12. The system of claim 1, wherein the one or more computer subsystems are further configured for determining third process information for one or more third features formed in one or more third areas on the specimen from the output, wherein at least a portion of the first process information is different than the third process information, wherein at least a portion of the design for the one or more first features is different than a design for the one or more third features, wherein the one or more first areas, the one or more second areas, and the one or more third areas are mutually exclusive on the specimen, and wherein the one or more computer subsystems are further configured for determining information for the first process information based on the third process information.
  13. The system of claim 1, wherein one or more of the first and second areas are located in a functional area of a device being formed on the specimen; or wherein one or more of the first and second areas are located in a scribe line area between devices being formed on the specimen; or wherein the inspection subsystem is further configured as an optical inspection subsystem.
  14. A computer-implemented method for determining metrology-like information for a specimen, comprising: generating output responsive to energy detected from a specimen by one or more output acquisition subsystems, wherein the one or more output acquisition subsystems comprise an inspection subsystem configured to generate at least a portion of the output responsive to the energy detected from the specimen while the energy is being scanned over the specimen; determining first process information for one or more first features formed in one or more first areas on the specimen from the output; and determining second process information for one or more second features formed in one or more second areas on the specimen from the output and at least a portion of the first process information, wherein at least a portion of the second process information is a different type of information than the first process information, wherein at least a portion of a design for the one or more second features is different than a design for the one or more first features, wherein the one or more first areas and the one or more second areas are mutually exclusive on the specimen, and wherein determining the first and second process information are performed by one or more computer subsystems coupled to the one or more output acquisition subsystems.
  15. A non-transitory computer-readable medium (800), storing program instructions (802) executable on a computer system (804) for performing a computer-implemented method for determining information for a specimen as recited in claim 14.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention generally relates to methods and systems for determining metrology-like information for a specimen using an inspection tool. 2. Description of the Related Art The following description and examples are not admitted to be prior art by virtue of their inclusion in this section. Fabricating semiconductor devices such as logic and memory devices typically includes processing a substrate such as a semiconductor wafer using a large number of semiconductor fabrication processes to form various features and multiple levels of the semiconductor devices. For example, lithography is a semiconductor fabrication process that involves transferring a pattern from a reticle to a resist arranged on a semiconductor wafer. Additional examples of semiconductor fabrication processes include, but are not limited to, chemical-mechanical polishing (CMP), etch, deposition, and ion implantation. Multiple semiconductor devices may be fabricated in an arrangement on a single semiconductor wafer and then separated into individual semiconductor devices. Inspection processes are used at various steps during a semiconductor manufacturing process to detect defects on reticles and wafers to promote higher yield in the manufacturing process and thus higher profits. Inspection has always been an important part of fabricating semiconductor devices such as ICs. However, as the dimensions of semiconductor devices decrease, inspection becomes even more important to the successful manufacture of acceptable semiconductor devices because smaller defects can cause the devices to fail. Defect review typically involves re-detecting defects detected as such by an inspection process and generating additional information about the defects at a higher resolution using either a high magnification optical system or a scanning electron microscope (SEM). Defect review is therefore performed at discrete locations on the specimen where defects have been detected by inspection. The higher resolution data for the defects generated by defect review is more suitable for determining attributes of the defects such as profile, roughness, more accurate size information, etc. Metrology processes are also used at various steps during a semiconductor manufacturing process to monitor and control the process. Metrology processes are different than inspection processes in that, unlike inspection processes in which defects are detected on a specimen, metrology processes are used to measure one or more characteristics of the specimen that cannot be determined using currently used inspection tools. For example, metrology processes are used to measure one or more characteristics of a specimen such as a dimension (e.g., line width, thickness, etc.) of features formed on the specimen during a process such that the performance of the process can be determined from the one or more characteristics. In addition, if the one or more characteristics of the specimen are unacceptable (e.g., out of a predetermined range for the characteristic(s)), the measurements of the one or more characteristics of the specimen may be used to alter one or more parameters of the process such that additional specimens manufactured by the process have acceptable characteristic(s). Metrology processes are also different than defect review processes in that, unlike defect review processes in which defects that are detected by inspection are re-visited in defect review, metrology processes may be performed at locations at which no defect has been detected. In other words, unlike defect review, the locations at which a metrology process is performed on a specimen may be independent of the results of an inspection process performed on the specimen. In particular, the locations at which a metrology process is performed may be selected independently of inspection results. In addition, since locations on the specimen at which metrology is performed may be selected independently of inspection results, unlike defect review in which the locations on the specimen at which defect review is to be performed cannot be determined until the inspection results for the specimen are generated and available for use, the locations at which the metrology process is performed may be determined before an inspection process has been performed on the specimen. Evolution of the semiconductor manufacturing industry is placing ever greater demands on yield management and in particular, on metrology and inspection systems. Critical dimensions are shrinking while wafer size is increasing. Economics is driving the industry to decrease the time for achieving high-yield, high-value production. Thus, minimizing the total time from detecting a yield problem to fixing it determines the return-on-investment for the semiconductor fabricator. Thus, inspection systems are evolving from stand-alone "tools" that just found defects to part of a more complete solution where detecting de