Growth Mechanism of Textured MgO Thin Films via SSCVD

Abstract

Magnesium oxide thin films have been deposited with use of single source chemical vapor deposition (SSCVD). The resultant films were examined by using transmission electron microscopy, X-ray texture analysis, and pole figure analysis. Due to the nature of the chemical reactions occurring at the surface during SSCVD growth, which result in a high growth rate/low flux environment, films of (111) orientation have been achieved without an amorphous underlayer, an unusual result for films of this orientation. Moreover the films have a strong degree of biaxial texturing in the x-y plane as found with X-ray texture analysis. These findings have important implications for buffer layers in perovskite thin film devices. The mechanism producing these structures has been revealed by using TEM and is discussed here.

Controlled synthesis and characterisation of MgOnanoparticles, thin films and polycrystalline nanorods derived from a Mg(ii) single source precursor

“…6) showed only the (111) and (222) reflections of cubic MgO, which indicates that highly (111)axis oriented films are obtained. Films of cubic MgO with preferential (200) as well as (111) orientation are well known and both type of textures can be obtained by gas-phase 13,17 and sol-gel 19,22 methods. In fcc oxides the (200) plane possesses the lowest surface energy and should therefore be thermodynamically favourable.…”

“…Growth along the [111] direction is, however, faster and can thus be kinetically favoured. 17 For the formation of a (111) preferential orientation it was suggested that an amorphous phase is formed first which then crystallises and exhibits the texture under influence of the substrate. 13,17,22 This is in good accordance with the situation presented in this work.…”

“…17 For the formation of a (111) preferential orientation it was suggested that an amorphous phase is formed first which then crystallises and exhibits the texture under influence of the substrate. 13,17,22 This is in good accordance with the situation presented in this work. After calcination at 210 C the films were still X-ray amorphous and the crystalline phase did not form before reaching 450 C sintering temperature.…”

“…Wet chemical techniques often employ spray pyrolysis of precursor solutions. 16,17 However, there are significantly less examples for the deposition from solution. Chemical bath deposition does not lead to MgO films directly, but yields hydromagnesite, which can be converted thermally to MgO in an additional step.…”

Synthesis and properties of Zn–Mg heterobimetallic carbamates. Crystal structures of the first reported single source precursors for ZnxMg1−xO thin films

“…SSCVD has been successfully employed in the past to prepare thin films of materials including ZnS, 9 ZnO 10 and MgO. 11, 12 In the instance of Zn x Mg 1−x O, the approach has the added advantage of providing a means of overcoming the difficulties associated with creating an alloyed material through an intimate mixing framework in situ at the growth interface, as this level of intimate mixing has already been achieved within the precursor molecule. The technique is highly desirable from a materials creation standpoint, but its utilisation poses a significant challenge to the synthetic chemist due to the stringent precursor requirements.…”