Effect of negative ions generation from sputtering target on crystalline orientation and kt2 of ScAlN thin films

Rui Kihara, Shinji Takayanagi, Takahiko Yanagitani

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Citations (Scopus)

Abstract

Large electromechanical coupling coefficient kt2 of the piezoelectric thin film is required for wide band operation in the bulk acoustic wave (BAW) filter. kt2 of AlN thin film was greatly improved by Sc doping. Sc metal usually contains carbon and oxygen impurities. Therefore, CN- and O- negative ions are generated from Sc sputtering target. As a result, crystalline orientation is degraded due to these negative ions bombardment to the substrate. We know that negative ions generation increase with increasing target temperature. In this study, to suppress negative ions generation from the target, Sc grains were embedded in water cooled Al metal disc target. ScAlN thin films were grown by RF magnetron sputtering. Two types of targets, where Sc grains are just put (heated) or those are embedded (cooled), are compared.

Original languageEnglish
Title of host publication2019 IEEE International Ultrasonics Symposium, IUS 2019
PublisherIEEE Computer Society
Pages1120-1123
Number of pages4
ISBN (Electronic)9781728145969
DOIs
Publication statusPublished - 2019 Oct
Event2019 IEEE International Ultrasonics Symposium, IUS 2019 - Glasgow, United Kingdom
Duration: 2019 Oct 62019 Oct 9

Publication series

NameIEEE International Ultrasonics Symposium, IUS
Volume2019-October
ISSN (Print)1948-5719
ISSN (Electronic)1948-5727

Conference

Conference2019 IEEE International Ultrasonics Symposium, IUS 2019
Country/TerritoryUnited Kingdom
CityGlasgow
Period19/10/619/10/9

Keywords

  • ScAlN
  • crystalline orientation
  • electromechanical coupling coefficient
  • negative ion
  • piezoelectric thin film

ASJC Scopus subject areas

  • Acoustics and Ultrasonics

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