Atomic layer deposition of pure In2O3 films for a temperature range of 200–300 °C using heteroleptic liquid In(DMAMP)2(OiPr) precursor

Abstract

In2O3 films were deposited by atomic layer deposition (ALD) using a newly synthesized heteroleptic In precursor, In(DMAMP)2(OiPr), and O3 at 150–300 °C. Self-limiting growth characteristics were exhibited for a wide ALD temperature range of 200–300 °C and growth rate of 0.029–0.033 nm/cycle. At a low temperature of 150 °C, the amorphous In2O3 film was deposited, while polycrystalline In2O3 films were achieved at 200–300 °C. The In2O3 films grown in this ALD temperature range had high densities of 7.0–7.2 g/cm3, which are comparable to those of bulk In2O3. At all growth temperatures (150–300 °C), no carbon or nitrogen impurities were detected, suggesting high reactivity of the In(DMAMP)2(OiPr) precursor. The ALD In2O3 films showed n-type electronic property with high electron concentrations of 1.6 × 1020–3.6 × 1020/cm3 and a Hall mobility of 31–39 cm2/V·s.