US 2019/0355601 A1 · PHASE FILTER FOR ENHANCED DEFECT DETECTION IN MULTILAYER STRUCTURE

Abstract

Disclosed are methods and apparatus for facilitating defect detection in a multilayer stack. The method includes selection of a set of structure parameters for modeling a particular multilayer stack and a particular defect contained within such particular multilayer stack and a set of operating parameters for an optical inspection system. Based on the set of structure and operating parameters, an electromagnetic simulation is performed of waves scattered from the particular multilayer stack and defect and arriving at a collection pupil of the optical inspection system. Based on the simulated waves at the collection pupil, a design of a phase filter having a plurality of positions for changing a plurality of phases within a plurality of corresponding positions of the collection pupil of the optical inspection tool is determined so as to compensate for an adverse effect of the particular multilayer stack on obtaining a defect signal for the defect within such particular multilayer stack and/or to enhance such defect signal. The design of the phase filter is then provided for fabrication or configuration of a phase filter inserted within the optical inspection system for detection of defects in multilayer stacks with the same structure parameters as the particular multilayer stack. Methods and systems for inspecting a multilayer stack for defects are also disclosed.

Claims20

Dependent claims

A method of facilitating defect detection in a multilayer stack, comprising:

selecting a set of structure parameters for modeling a particular multilayer stack and a particular defect contained within such particular multilayer stack and a set of operating parameters for an optical inspection system;
based on the set of structure and operating parameters, performing an electromagnetic simulation of waves scattered from the particular multilayer stack and defect and arriving at a collection pupil of the optical inspection system;
based on the simulated waves at the collection pupil, determining a design of a phase filter having a plurality of positions for changing a plurality of phases at a plurality of corresponding positions within the collection pupil of the optical inspection tool so as to compensate for an adverse effect of the particular multilayer stack on obtaining a defect signal for the defect within such particular multilayer stack and/or to enhance such defect signal;
and
providing the design of the phase filter for fabrication or configuration of a phase filter inserted within the optical inspection system for detection of defects in multilayer stacks with the same structure parameters as the particular multilayer stack.

2 more elements

A method of inspecting a multilayer stack in an optical inspection tool, comprising:

in the inspection tool, providing a phase filter having a plurality of positions for changing a plurality of phases at a plurality of positions of a collection pupil of the inspection tool, wherein the phase filter was designed to compensate for an adverse effect of a particular multilayer stack on obtaining a defect signal for a defect, if any, within such particular multilayer stack and/or to enhance such defect signal;
generating an image based on light scattered from the particular multilayer stack in response to an incident beam directed towards such particular multilayer stack;
and
determining whether the particular multilayer stack has a defect based on the image.

1 more element

An inspection system for detecting defects in a multilayer stack, the system comprising:

a light source for generating an illumination beam;
an illumination lens system for directing the illumination beam towards a multilayer stack;
a collection lens system for directing towards a detector scattered light from a multilayer stack in response to the illumination beam, wherein the collection lens system includes a phase filter having a plurality of positions for changing a plurality of phases at a plurality of positions within a collection pupil of the system, wherein the phase filter was designed to compensate for an adverse effect of a particular multilayer stack on obtaining a defect signal for a defect, if any, within such particular multilayer stack and/or to enhance such defect signal;
the detector for receiving the scattered light from a multilayer stack;
and
a controller operable to perform the following operations:
generating an image based on light scattered from the particular multilayer stack in response to an incident beam directed towards the particular multilayer stack;
and
determining whether the particular multilayer stack has a defect based on the image.

6 more elements

Dependencies are inferred from the claim text.

Phase filter for enhanced defect detection in multilayer structure

Life of this patent

Phase filter for enhanced defect detection in multilayer structure

Life of this patent

Abstract

Claims20