Method and system for noise mitigation in multi-beam scanning electron microscopy system

Abstract

A scanning electron microscopy system is disclosed. The system includes a multi-beam scanning electron microscopy (SEM) sub-system. The SEM sub-system includes a multi-beam electron beam source configured to generate a plurality of electron beams, a sample stage configured to secure a sample, an electron-optical assembly, and a detector assembly configured to detect a plurality of electron signalbeams emanating from the surface of the sample to form a plurality of images, each image associated with an electron beam of the plurality of electron beams. The system includes a controller configured to receive the images from the detector assembly, compare two or more of the images to identify common noise components present in the two or more images, and remove the identified common noise components from one or more images of the plurality of images.

Description

[0001] Cross References to Related Applications [0002] The inventors claimed in this application under 35 U.S.C. §119(e) are Mark McCord, Rainer Knippelmeyer, Douglas Masnaghetti, and Richard Simon ( Richard Simmonrs, U.S. Provisional Application Serial No. 62 / 221,599, filed September 21, 2015, entitled "TECHNIQUEFOR NOISE REJECTION IN A MULTIPLE-BEAM IMAGING SYSTEM" and constitutes a formal (non-provisional) patent application to said U.S. Provisional Application, which is hereby incorporated by reference in its entirety. technical field [0003] The present invention relates generally to scanning electron microscopy, and more particularly to noise reduction in multi-beam electron microscopy systems. Background technique [0004] The fabrication of semiconductor devices, such as logic and memory devices, typically involves processing a substrate, such as a semiconductor wafer, using a number of semiconductor fabrication processes to form various features and multiple le...

AI Technical Summary

Problems solved by technology

In single-beam SEM systems, it is often difficult to separate noise from image information

This difficulty arises from the fact that: i) it is difficult to determine that image artifacts are noise and not actual image features; and ii) there may not be enough characteristic information in a single image to extract noise (such as straight sharp edges)

In the case of implementing a multi-beam SEM system, inspection time is greatly reduced due to simultaneous acquisition of image data from multiple regions of the sample, however, noise reduction techniques in multi-beam SEM systems have proven ineffective

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