Reduction of Incubation Period by Employing OH-Terminated Si(001) Substrates in the Atomic Layer Deposition of Al₂O₃

Abstract

The phenomenon of low initial growth rates in atomic layer deposition (ALD) of various oxides on HF-treated (thus H-terminated) Si(001) substrates, which is termed the incubation effect or incubation period, can be effectively avoided by use of OH-terminated Si(001) substrates. Two ways of preparing OH-terminated Si(001) were devised in this work: one from atomically clean Si(001) and the other from H-terminated Si(001). The effect of reducing the incubation period was confirmed in the ALD process of aluminum oxide (Al 2 O 3 ) thin films in which trimethylaluminum and water were used as sources of aluminum and oxygen, respectively. The use of OH-terminated Si(001) substrates has another beneficial effect of producing thin films with very smooth surface morphology. We propose the use of OH-terminated Si(001) substrates for growing thin films of many other metal oxides that have shown the incubation period on H-terminated Si(001) substrates.