Thin film thickness adjustments for three-dimensional interferometric measurements

Patent metadata

Field	Value
Publication number	US-12584733-B2
Application number	US-202318230613-A
Country	US
Kind code	B2
Filing date	Aug 4, 2023
Priority date	Aug 4, 2023
Publication date	Mar 24, 2026
Grant date	Mar 24, 2026

Abstract

A 3D surface map of a workpiece is determined using an interferometric quantitative phase imaging technique. The workpiece includes a transparent thin film or layers stack. The 3D surface map is corrected based on a thickness and a refractive index of the transparent thin film or layers stack. This technique can be used with an inspection system configured to perform an interferometric quantitative phase imaging.

First claim

What is claimed is:

1 . A system comprising:
a stage configured to hold a workpiece; an inspection system configured to perform an interferometric quantitative phase imaging; and a processor in electronic communication with the inspection system, wherein the processor is configured to:
determine a 3D surface map that includes height information in a 2D arrangement from a phase map, wherein the workpiece includes a transparent thin film or layers stack near or on a feature, and wherein the phase map is generated from phase imaging data; and
correct at least one value in the height information of the 3D surface map based on a thickness and a complex refractive index of the transparent thin film or layers stack.

2 . The system of claim 1 , wherein the feature is a bump, a micro-bump, a pillar, a metal-nail, an electronic device, or a transparent feature.

3 . The system of claim 1 , wherein the workpiece is a semiconductor wafer, flat panel, printed circuit board, or glass substrate.

4 . The system of claim 1 , further including a reflectometer configured to measure the thickness and the refractive index.

5 . The system of claim 1 , wherein the correcting uses a phase shift correction.

6 . The system of claim 5 , wherein the transparent thin film or layers stack technique uses only one wavelength, dual wavelength, or multi-wavelength illumination.

7 . The system of claim 1 , wherein the interferometric quantitative phase imaging uses coherent illumination, non-coherent illumination, or partially-coherent illumination.

8 . A method comprising:
determining a 3D surface map of a workpiece using an interferometric quantitative phase imaging technique, wherein the workpiece includes a transparent thin film or layers stack near or on a feature, and wherein the 3D surface map includes height information in a 2D arrangement; measuring a thickness and a refractive index using a reflectometer; and correcting, using a processor, at least one value in the height information of the 3D surface map based on the thickness and the refractive index of the transparent thin film or layers stack.

9 . The method of claim 8 , wherein the feature is a bump, a micro-bump, a pillar, a metal-nail, an electronic device, or a transparent feature.

10 . The method of claim 8 , wherein the workpiece is a semiconductor wafer, flat panel, printed circuit board, or glass substrate.

11 . The method of claim 8 , wherein the correcting uses a phase shift correction.

12 . The method of claim 11 , wherein the transparent thin film or layers stack technique uses only one wavelength, dual wavelength, or multi-wavelength illumination.

13 . The method of claim 8 , wherein the interferometric quantitative phase imaging uses coherent illumination, non-coherent illumination, or partially-coherent illumination.

14 . The method of claim 8 , wherein the thickness is based on a measured phase difference between two points on the workpiece.

15 . The method of claim 8 , wherein the refractive index has a real part and an imaginary part.

16 . A non-transitory computer-readable storage medium, comprising one or more programs for executing the following steps on one or more computing devices comprising:
determining a 3D surface map of a workpiece from data generated using an interferometric quantitative phase imaging technique, wherein the workpiece includes a transparent thin film or layers stack near or on a feature, and wherein the 3D surface map includes height information in a 2D arrangement; correcting at least one value in the height information of the 3D surface map based on a thickness and a refractive index of the transparent thin film or layers stack.

17 . The non-transitory computer-readable storage medium of claim 16 , wherein the feature is a bump, a micro-bump, a pillar, a metal-nail, an electronic device, or a transparent feature.

18 . The non-transitory computer-readable storage medium of claim 16 , wherein the workpiece is a semiconductor wafer, flat panel, printed circuit board, or glass substrate.

19 . The non-transitory computer-readable storage medium of claim 16 wherein the correcting uses a phase shift correction.

Assignees

• Orbotech Ltd

Inventors

• Yoav Nachum
• Lovsky Yulia
• Levy Ronen

Classifications

• G01B2210/56

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

• G01B9/02075

  of particular errors · CPC title

• G01B9/02029

  Combination with non-interferometric systems, i.e. for measuring the object · CPC title

• G01B9/0207

  Error reduction by correction of the measurement signal based on independently determined error sources, e.g. using a reference interferometer · CPC title

• G01N21/9501

  Semiconductor wafers (manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20) · CPC title