Determination of customized components for fitting wafer profile

Patent metadata

Field	Value
Publication number	US-11788833-B2
Application number	US-202016888235-A
Country	US
Kind code	B2
Filing date	May 29, 2020
Priority date	Apr 17, 2015
Publication date	Oct 17, 2023
Grant date	Oct 17, 2023

Abstract

Method and system for defining basis functions for fitting distortions of profiles of objects in a batch, that has undergone a fabrication process, in a manner adaptable to the fabrication process to reduce the errors between profiles approximated with the use of such basis functions and actual object profiles. Process-specific individual basis functions are defined based on spatially-dense measurement of objects from training sub-set of the batch and applying learning algorithm to results of such measurement. Advantages of process-adaptable basis functions over generic basis functions for fitting distortion shapes of objects include higher accuracy of fitting either at larger or a fewer locations across the object.

First claim

What is claimed:

1. A method comprising:
measuring multiple features on a set of workpieces to acquire measurement data;
generating a set of functions, derived from the measurement data, that characterize distortions of the workpieces from the set, comprising:
measuring distortion profiles at a plurality of spatial locations across a workpiece from the set of workpieces;
defining, based on a Principal Component Analysis (PCA) technique, a set of distortion functions from the measured distortion profiles, wherein the set of distortion functions correspond with a set of weights, wherein one weight of the set of weights relates to a relative contribution of one corresponding distortion function of the set of distortion functions; and
selecting a predetermined number of distortion functions from the set of distortion functions having a highest weight to obtain the set of functions;

applying the set of functions to characterize distortions of one or more workpieces to be processed; and
processing the one or more workpieces while compensating the distortion thereof using the set of functions.

2. A method according to claim 1 , further comprising processing the one or more workpieces while compensating for the characterization of the one or more workpieces.

3. A method according to claim 2 , wherein the processing the one or more workpieces includes bonding a workpiece from the one or more workpieces to an identified unit.

4. A method according to claim 2 , wherein the measuring the distortion profiles includes measuring a spatial profile of a workpiece from the set of workpieces, and wherein the applying the set of functions includes defining an approximated spatial profile of a workpiece.

5. A method according to claim 4 , wherein the measuring the distortion includes simultaneously measuring the workpiece with multiple sensors.

6. A method according to claim 1 , wherein the measuring the distortion profiles includes: with a shape-profiling tool and for each workpiece from the set of workpieces, measuring a corresponding spatial profile at M spatial locations across said workpiece to determine a measured spatial profile.

7. A system comprising:
at least one of a lithographic exposure tool having an optical projection system and a workpiece bonding apparatus;
a spatial profiling tool;
programmable electronic circuitry in operable communication with at least one of the lithographic exposure tool and the spatial profiling tool; and
tangible, non-transient storage memory in electronic communication with said circuitry, the memory having thereon program code configured to cause the circuitry to determine spatial profiles of a set of workpieces processed with the exposure tool by at least:
determining a set of functions by assessing data representing the workpieces with a process analysis technique, comprising:
measuring the spatial profiles at a plurality of spatial locations across a workpiece from the set of workpieces;
defining, based on a Principal Component Analysis (PCA) technique, a set of distortion functions from the measured spatial profiles, wherein the spatial profiles correspond with a set of weights, wherein one weight of the set of weights relates to a relative contribution of one corresponding spatial profile of the spatial profiles; and
selecting a predetermined number of spatial profiles from the spatial profiles having a highest weight to obtain the set of functions;

applying the set of functions to characterize distortions of one or more workpieces to be processed; and
processing the one or more workpieces while compensating the distortion thereof using the set of functions.

8. The system of claim 7 , wherein the workpiece bonding apparatus is further configured to bond first and second workpieces, approximated spatial profiles for which have been defined.

9. The system of claim 7 , wherein the lithographic exposure tool is configured to process the one or more workpieces while compensating for the characterization of the one or more workpieces.

10. The system of claim 9 , wherein the processing the one or more workpieces includes bonding a workpiece from the one or more workpieces to an identified unit.

11. The system of claim 9 , wherein the measuring the distortion profiles includes measuring a spatial profile of a workpiece from the set of workpieces, and wherein the applying the set of functions includes defining an approximated spatial profile of a workpiece.

12. The system of claim 11 , wherein the measuring the distortion includes simultaneously measuring the workpiece with multiple sensors.

13. The system of claim 7 , wherein the measuring the distortion profiles includes: with the spatial profiling tool and for each workpiece from the set of workpieces, measuring a corresponding spatial profile at M spatial locations across said workpiece to determine a measured spatial profile.

Assignees

• Nikon Corp

Inventors

• Bow Travis D
• Pang Henry
• Hashemi Fardad A

Classifications

• G01B11/24 Primary

  for measuring contours or curvatures · CPC title

• G03F7/70783

  Handling stress or warp of chucks, masks or workpieces, e.g. to compensate for imaging errors or considerations related to warpage of masks or workpieces due to their own weight · CPC title

• G03F9/7003

  Alignment type or strategy, e.g. leveling, global alignment · CPC title

• G01B2210/56

  Measuring geometric parameters of semiconductor structures, e.g. profile, critical dimensions or trench depth · CPC title