Aperture-time of oxygen-precursor for minimum silicon incorporation into the interface-layer in atomic layer deposition-grown HfO2/Si nanofilms

作者：Giovanni Mani Gonzalez Pierre; Oswaldo Vazquez Lepe Milton; Herrera Gomez Alberto

来源：Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films , 2015, 33(1): UNSP 010602.

DOI：10.1116/1.4904496

Hafnium oxide nanofilms were grown with atomic layer deposition on H-terminated Si (001) wafers employing tetrakis dimethyl amino hafnium (TDMA-Hf) and water as precursors. While the number of cycles (30) and the aperture-time for TDMA-Hf (0.08 s) were kept constant, the aperture-time (tau H2O) for the oxidant-agent (H2O) was varied from 0 to 0.10 s. The structure of the films was characterized with robust analysis employing angle-resolved x-ray photoelectron spectroscopy. In addition to a similar to 1 nm hafnium oxide layer, a hafnium silicate interface layer, also similar to 1 nm thick, is formed for tau(H2O) > 0. The incorporation degree of silicon into the interface layer (i. e., the value of 1 - x in HfxSi1-xOy) shows a minimum of 0.32 for tau(H2O) = 0.04 s. By employing the simultaneous method during peak-fitting analysis, it was possible to clearly resolve the contribution from the silicate and from oxide to the O 1s spectra, allowing for the assessment of the oxygen composition of each layer as a function of oxidant aperture time. The uncertainties of the peak areas and on the thickness and composition of the layers were calculated employing a rigorous approach.

• 出版日期2015-1