AVS 57th International Symposium & Exhibition
    Applied Surface Science Tuesday Sessions
       Session AS-TuP

Paper AS-TuP3
Thickness and Composition of the HfO2/Si Interface Layer As a Function of Aperture-Time of Oxidant-Agent for ALD-grown HfO2 Nanofilms

Tuesday, October 19, 2010, 6:00 pm, Room Southwest Exhibit Hall

Session: Applied Surface Science Poster Session
Presenter: P.G. Mani-Gonzalez, CINVESTAV Queretaro, Mexico
Authors: P.G. Mani-Gonzalez, CINVESTAV Queretaro, Mexico
M.O. Vazquez-Lepe, CINVESTAV Queretaro, Mexico
A. Herrera-Gomez, CINVESTAV Queretaro, Mexico
Correspondent: Click to Email
Hafnium oxide nanofilms were grown with ALD (Atomic Layer Deposition) on H-terminated Si(001) wafers employing TDMA-Hf (tetrakis dimetil animo hafnium) and water as precursors. The structure of the films was characterized with angle-resolved X-ray photoelectron spectroscopy (ARXPS). While the aperture-time for TDMA-Hf was kept constant at 0.08 s during the ALD deposition, the aperture-time (t H2O) for the oxidant-agent (H2O) was varied from 0 to 0.1 s among the different samples. The water exposition-time has a direct effect on the thickness of the HfO2 layer, which saturates at ~ 1.7 nm for 30-cycle ALD processes. The composition and thickness of the interface between Si and hafnia is approximately constant at Hf0.5Si0.5O2 and 1 nm for 0.02 < t H2O <0.06 s. For larger aperture-times, the Hf contribution to the composition rises slowly; the thickness of the layer also rises slowly. The total film thickness, including the hafnium silicate and hafnium oxide layers, saturates at ~ 3 nm. Our results are in accordance with prior results, which estimate the film growth rate at ~ 1 Å per ALD cycle.