Investigation of Antimony Oxide Films Deposited by Atomic Layer Deposition

Abstract

Atomic layer deposition of antimony oxide thin films was investigated in a temperature range between 50 and 250 °C using triethylantimony and ozone. Layer thickness was measured by spectroscopic ellipsometry using adapted layer models. It was proved that homogenous deposition could be achieved on flat silicon wafers and in trench structures. Little growth was found below 100 °C deposition temperature and linear temperature dependence on the growth rate between 100 and 250 °C. High-resolution transmission electron microscope measurements of as-deposited films showed the existence of SiO2 interface layer and crystalline grains within the antimony oxide. The thermal stability of antimony oxide layers was investigated by rapid thermal annealing experiments in the temperature range of 500 to 850 °C. The layers were not stable above 700 °C, which was assumed to be the reason for failing to apply this material as dopant source for ultra-shallow antimony doping of silicon so far.