Atomic Layer Deposition Of Cr_2o_3 Thin Films: Effect Of Crystallization On Growth And Properties

摘要

Atomic layer deposition of Cr_2O_3 thin films from CrO_2Cl_2 and CH_3OH on amorphous SiO_2 and crystalline Si(100) and α-Al_2O_3(1102) substrates was investigated, and properties of the films were ascertained. Self-limited growth with a rate of 0.05-0.1 nm/cycle was obtained at substrate temperatures of 330-420 ℃. In this temperature range epitaxial eskolaite was formed on the α-Al_2O_3(1102) substrates. The predominant crystallographic orientation in the epitaxial films depended, however, on the growth temperature and film thickness. Sufficiently thick films grown on the SiO_2 and Si(10 0) substrates contained also the eskolaite phase, but thinner films deposited at 330-375 ℃ on these substrates were amorphous. The growth rate data of films with different phase composition allowed a conclusion that the crystalline phase grew markedly faster than the amorphous phase did. The amorphous, polycrystalline and epitaxial films had densities of 4.9, 5.1 and 5.1-5.3 g/cm~3, respectively.