Closed-loop autofocus scheme for scanning electron microscope

Le Cui, Naresh Marturi, Eric Marchand, Sounkalo Dembélé, Nadine Piat

Research output: Contribution to journalConference articlepeer-review

Abstract

In this paper, we present a full scale autofocus approach for scanning electron microscope (SEM). The optimal focus (in-focus) position of the microscope is achieved by maximizing the image sharpness using a vision-based closed-loop control scheme. An iterative optimization algorithm has been designed using the sharpness score derived from image gradient information. The proposed method has been implemented and validated using a tungsten gun SEM at various experimental conditions like varying raster scan speed, magnification at real-time. We demonstrate that the proposed autofocus technique is accurate, robust and fast.

Original languageEnglish
Article number05003
JournalMATEC Web of Conferences
Volume32
DOIs
Publication statusPublished - 2 Dec 2015
EventInternational Symposium of Optomechatronics Technology, ISOT 2015 - Neuchatel, Switzerland
Duration: 14 Oct 201516 Oct 2015

Bibliographical note

Publisher Copyright:
© 2015 Owned by the authors, published by EDP Sciences.

ASJC Scopus subject areas

  • General Chemistry
  • General Materials Science
  • General Engineering

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