Feed Forward of Metrology Data in a Metrology System

Patent metadata

Field	Value
Publication number	US-2016290796-A1
Application number	US-201615090389-A
Country	US
Kind code	A1
Filing date	Apr 4, 2016
Priority date	Apr 6, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

A metrology performance analysis system includes a metrology tool including one or more detectors and a controller communicatively coupled to the one or more detectors. The controller is configured to receive one or more metrology data sets associated with a metrology target from the metrology tool in which the one or more metrology data sets include one or more measured metrology metrics and the one or more measured metrology metrics indicate deviations from nominal values. The controller is further configured to determine relationships between the deviations from the nominal values and one or more selected semiconductor process variations, and determine one or more root causes of the deviations from the nominal values based on the relationships between values of the one or more metrology metrics and the one or more selected semiconductor process variations.

First claim

1 . A metrology performance analysis system, comprising:
a metrology tool including one or more detectors; and a controller communicatively coupled to the one or more detectors, the controller including one or more processors configured to execute program instructions configured to cause the one or more processors to:
receive one or more metrology data sets associated with a metrology target from the metrology tool, wherein the one or more metrology data sets include one or more measured metrology metrics, wherein the one or more measured metrology metrics indicate one or more deviations from one or more nominal values;
determine one or more relationships between the one or more deviations from the one or more nominal values and one or more selected semiconductor process variations; and
determine one or more root causes of the one or more deviations from the one or more nominal values based on the one or more relationships between the one or more deviations from the one or more nominal values and the one or more selected semiconductor process variations.

2 . The system of claim 1 , wherein the determining one or more relationships between the one or more deviations from the one or more nominal values and the one or more selected semiconductor process variations further comprises:
generating a geometric model of the metrology target; simulating one or more metrology metrics based on the geometric model of the metrology target; generating a perturbed geometric model of the metrology target, wherein the perturbed geometric model includes one or more alterations of the metrology target caused by the one or more selected semiconductor process variations; simulating one or more variations of the one or more metrology metrics based on the one or more selected semiconductor process variations to determine the one or more relationships between the one or more deviations from the one or more nominal values and the one or more selected semiconductor process variations.

3 . The system of claim 1 , wherein the metrology target is an overlay target.

4 . The system of claim 3 , wherein the overlay target includes a grating-over-grating overlay target.

5 . The system of claim 1 , wherein the one or more metrology metrics include at least one of a pupil image metric, precision, tool-induced shift, sensitivity, diffraction efficiency, or through-focus slope.

6 . The system of claim 1 , wherein the one or more metrology data sets include non-overlay data.

7 . The system of claim 1 , wherein the one or more selected semiconductor process variations include at least one of a film thickness, a real refractive index value associated with one or more wavelengths, an imaginary refractive index value associated with one or more wavelengths, planarity, stress, strain, a critical dimension, dishing, erosion, or a side wall angle.

8 . The system of claim 1 , wherein the one or more processors are further configured to execute program instructions configured to cause the one or more processors to:
modify a recipe of the one or more selected semiconductor processes based on the root cause.

9 . The system of claim 8 , wherein the modifying the recipe of the one or more selected semiconductor processes comprises:
modifying at least one of a wavelength or a polarization of an illumination beam associated with the metrology tool.

10 . The system of claim 1 , wherein the one or more processors are further configured to execute program instructions configured to cause the one or more processors to:
direct the metrology tool replace the metrology target with an alternative metrology target based on the root cause.

11 . The system of claim 10 , wherein the directing the metrology tool replace the metrology target with an alternative metrology target based on the root cause causes a reduction of the one or more deviations from one or more nominal values.

12 . The system of claim 1 , wherein the metrology tool includes an ellipsometer.

13 . The system of claim 12 , wherein the ellipsometer includes at least one of a single-wavelength ellipsometer, a spectroscopic ellipsometer, or an angle-resolved ellipsometer.

14 . The system of claim 13 , wherein the ellipsometer includes a plurality of illumination beams directed to the metrology target at a plurality of angles of illumination.

15 . The system of claim 13 , wherein the spectroscopic ellipsometer measures Mueller matrix elements.

16 . The system of claim 1 , wherein the metrology tool includes a reflectometer.

17 . The system of claim 16 , wherein the reflectometer includes at least one of a single-wavelength reflectometer, a spectroscopic reflectometer, or an angle-resolved reflectometer.

18 . The system of claim 1 , wherein the metrology tool includes an imaging system.

19 . The system of claim 18 , wherein the imaging system includes at least one of a pupil imaging system or a spectral imaging system.

20 . The system of claim 1 , wherein the metrology tool includes an angle-resolved scatterometer with a pupil imaging system.

21 . The system of claim 20 , wherein one or more measured metrology metrics are extracted from a pupil image, wherein the metrology target is a grating-over-grating structure.

22 . The system of claim 21 , wherein the one or more measured metrology metrics include a pupil feature in the pupil image.

23 . The system of claim 22 , wherein the one or more relationships between the one or more deviations from the one or more nominal values and the one or more selected semiconductor process variations include a variation of a location of the pupil feature in the pupil image associated with a symmetric selected semiconductor process variation.

24 . The system of claim 22 , wherein the one or more relationships between the one or more deviations from the one or more nominal values and the one or more selected semiconductor process variations include a variation of a strength of the pupil feature in the pupil image associated with an asymmetric selected semiconductor process variation.

25 . The system of claim 22 , wherein the one or more relationships between the one or more deviations from the one or more nominal values and the one or more selected semiconductor process variations include a variation of a sign of the pupil feature in the pupil image associated with a directionality of an asymmetric selected semiconductor process variation.

26 . The system of claim 25 , wherein the directionality of the asymmetric selected semiconductor process variation comprises:
a directionality of a side wall angle asymmetry.

27 . The system of claim 1 , wherein determining the one or more root causes includes generating a map of one or more values of the one or more measured metrology metrics at one or more locations on a wafer surface.

28 . The system of claim 1 , wherein the metrology tool further comprises:
an illumination source configured to generate an illumination beam; an imaging system configured to direct the illumination beam onto the metrology target; and one or more collection optics configured to capture at least a portion of the illumination beam incident on the metrology target to the one or more detectors to generate the one or more metrology data sets.

29 . The system of claim 1 , wherein the controller is integrated within the metrology tool

Assignees

• Kla Tencor Corp

Inventors

• Levy Ady
• Kandel Daniel
• Adel Michael E
• Poslavsky Leonid
• Robinson John
• Marciano Tal
• Bringoltz Barak
• Grunzweig Tzahi
• Klein Dana
• Itzkovich Tal
• Carmel Nadav
• Amir Nuriel
• Ramanathan Vidya
• Camp Janay
• Wagner Mark

Classifications

• G03F7/70533

  Controlling abnormal operating mode, e.g. taking account of waiting time, decision to rework or rework flow · CPC title

• G01N21/31

  Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry {(G01N21/72 takes precedence)} · CPC title

• G01N2021/213

  Spectrometric ellipsometry · CPC title

• G01N21/4738

  Diffuse reflection (precedence is given to G01N21/55 - G01N21/57 if specular component is taken into consideration), e.g. also for testing fluids, fibrous materials · CPC title

• G01N21/41

  Refractivity; Phase-affecting properties, e.g. optical path length (G01N21/21 takes precedence) · CPC title