Formation of oxide thin films from reactions of hydrogen peroxide vapour with gas mixtures containing silane and other hydrides

Abstract

When hydrogen peroxide vapour and silane are mixed appropriately at low pressure a self-planarising layer of silica is formed by a surface phase reaction. The effect on the reaction of replacing part of the SiH4 with GeH4, PH3 and B2H6 has now been studied. Using GeH4-SiH4 mixtures containing up to 27 GeH4, self-planarising, Ge-Si-O films, rich in germanium were obtained. Films formed by oxidising the same GeH4-SiH4 mixtures with plasma cracked water vapour were not self-planarising and contained much less germanium. The mixed oxide films from reacting PH3-SiH4 or B2H6-SiH4 mixtures with H2O2 vapour were also not self-planarising but were spectroscopically similar to known phosphosilicate or borosilicate glasses.