CVD of TixSi1-xO2 films: Precursor chemistry impacts film composition

Ryan C. Smith, Noel Hoilien, Craig Dykstra, Stephen A. Campbell, Jeffrey T. Roberts, Wayne L. Gladfelter

Research output: Contribution to journalArticlepeer-review

25 Scopus citations

Abstract

Thin films of composition TixSi1-xO2 were grown by low-pressure (LP) CVD on silicon (100) substrates using tetraethyl orthosilicate (TEOS), [Si(OC2H5)4], and either titanium isopropoxide (TTIP), [Ti(O-'Pr)4], or anhydrous titanium tetranitrate (TN), [Ti(NO3)4], as the sources of SiO 2 and TiO2, respectively. The substrate temperature was varied between 300 °C and 535 °C, and the individual precursor delivery rates ranged from 5 seem to 100 seem. Under these conditions, growth rates ranging from 0.6 nm min-1 to 90.0 nm min-1 were observed. As-deposited films were amorphous to X-rays, and cross-sectional transmission electron microscopy (TEM) images showed no compositional inhomogeneity. Rutherford backscattering (RBS) spectrometry revealed that the relative concentration of TiO2 and SiO2 was dependent upon the choice of TiO2 precursor. Possible multi-precursor deposition scenarios are presented and discussed in relation to the observed variation of film stoichiometry. For the TTIP-TEOS pair, the systematic variation of Ti content with deposition conditions could be accounted for by a growth scenario that limits SiO2 growth to TiO2 sites within the composite film. For the case of TN-TEOS the Ti content remained close to 50 % for all conditions studied. A specific chemical reaction between TN and TEOS prior to film deposition accounts for the observed composition.

Original languageEnglish (US)
Pages (from-to)79-86
Number of pages8
JournalChemical Vapor Deposition
Volume9
Issue number2
DOIs
StatePublished - Mar 2003

Keywords

  • Dielectrics
  • Titanium isopropoxide
  • Titanium nitrate

Fingerprint Dive into the research topics of 'CVD of Ti<sub>x</sub>Si<sub>1-x</sub>O<sub>2</sub> films: Precursor chemistry impacts film composition'. Together they form a unique fingerprint.

Cite this