Atomic layer deposition of LiF thin films from Lithd, Mg(thd)2, and TiF4 precursors

Research output: Contribution to journalArticleScientificpeer-review

Researchers

  • Miia Mäntymäki

  • Jani Hämäläinen
  • Esa Puukilainen
  • Timo Sajavaara
  • Mikko Ritala
  • Markku Leskelä

Research units

  • University of Helsinki
  • University of Jyväskylä

Abstract

Lithium fluoride is an interesting material because of its low refractive index and large band gap. Previously LiF thin films have been deposited mostly by physical methods. In this study a new way of depositing thin films of LiF using atomic layer deposition (ALD) is presented. Mg(thd)2, TiF 4 and Lithd were used as precursors, and they produced crystalline LiF at a temperature range of 300-350 C. The films were studied by UV-vis spectrometry, field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), atomic force microscopy (AFM), time-of-flight elastic recoil detection analysis (ToF-ERDA), and energy dispersive X-ray spectroscopy (EDX). In addition, film adhesion was tested by a Scotch tape test. This method results in LiF films with a growth rate of approximately 1.4 Å per cycle. According to the ToF-ERDA measurements, the films are pure LiF with very small Mg and Ti impurities, the largest impurity being hydrogen with contents below 1 atom %.

Details

Original languageEnglish
Pages (from-to)1656-1663
Number of pages8
JournalChemistry of Materials
Volume25
Issue number9
Publication statusPublished - 14 May 2013
MoE publication typeA1 Journal article-refereed

    Research areas

  • ALD, atomic layer deposition, LiF, lithium fluoride, thin films

ID: 28852948