Line-to-line repetitive control of a 6-DoF hexapod stage for overlay measurements using Atomic Force Microscopy

Gert Witvoet, Joost Peters, Stefan Kuiper, Tom Oomen

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

2 Citations (Scopus)

Abstract

The overlay performance between different layers of semiconductor devices is a key parameter for correct functionality of such devices. With device features getting increasingly smaller, there is a need for novel and more accurate overlay metrology tools. This paper aims to increase the positioning accuracy of such a novel metrology machine below the nanometer by the application of repetitive control. At the heart of the machine is a large stroke 6-DoF hexapod motion stage, carrying a sub-nanometer accurate AFM head, whose positioning accuracy during scanning is a key performance driver. The sample under examination during scanning effectively forms an unknown repetitive disturbance on its feedback loop. For this reason a line-to-line repetitive controller in combination with decentralized feedback has been employed, in which the base harmonic is defined by one full line-scan. Experimental results on the machine with an emulated sample demonstrate a significant performance improvement, achieving nanometer accurate positioning while scanning. This shows that repetitive control in a line-to-line domain is a potential enabler for AFM-based overlay nanometrology.

Original languageEnglish
Title of host publication2019 American Control Conference, ACC 2019
Place of PublicationPiscataway
PublisherInstitute of Electrical and Electronics Engineers
Pages2464-2469
Number of pages6
ISBN (Electronic)978-1-5386-7926-5
DOIs
Publication statusPublished - 1 Jul 2019
Event2019 American Control Conference, ACC 2019 - Philadelphia, United States
Duration: 10 Jul 201912 Jul 2019
http://acc2019.a2c2.org

Conference

Conference2019 American Control Conference, ACC 2019
Abbreviated titleACC2019
CountryUnited States
CityPhiladelphia
Period10/07/1912/07/19
Internet address

Fingerprint Dive into the research topics of 'Line-to-line repetitive control of a 6-DoF hexapod stage for overlay measurements using Atomic Force Microscopy'. Together they form a unique fingerprint.

Cite this