Ιn situ N2-NH3 plasma pre-treatment of silicon substrate enhances the initial growth and restricts the substrate oxidation during alumina ALD

Abstract

This is an author's version published in: http://oatao.univ-toulouse.fr/24356 AbstractThe initial substrate inhibited island growth and the formation of an interfacial layer with uncontrollable characteristics are two main drawbacks of the Atomic Layer Deposition (ALD) of high-k metal-oxide gate dielectrics on silicon (Si). In this paper, we investigate the ALD of Al2O3 films from TMA and H2O, on HF-cleaned, as well as on HFcleaned and in situ N2-NH3 plasma pretreated Si between 0 and 75 cycles. The films and their interface were characterized via Scanning Transmission Electron Microscopy (STEM) coupled to Energy Dispersive X-ray spectroscopy (EDX). The initial deposition is clearly increased on the pretreated surfaces, obtaining a linear ALD regime even after 5 ALD cycles, compared to several tens of cycles needed on HF-cleaned Si. Furthermore, a SixNy layer is formed by the N2-NH3 plasma pretreatment, which acts as a barrier layer, reducing the oxidation of the Si substrate beneath it. This analysis provides a general framework for the understanding and determination of adequate surface pretreatments, able to combat the substrate inhibited initial growth and the Si oxidation during metal-oxide ALD on Si.

Influence of the Cl2 etching on the Al2O3/GaN metal–oxide–semiconductor interface

“…This confirms the low reactivity of the C-terminated and the Cl-terminated surfaces, resulting from the air exposure and plasma etching, toward the ALD reactants. Similar behavior was also found during Al2O3 ALD processes on Si when using NH3/N2 pretreatments prior to the ALD 27 .…”

Metal and metal oxide nanoparticle toxicity: moving towards a more holistic structure–activity approach

“…[1][2][3] The plethora of applications in electronics, 4 medicine, 5 food, 6 energy 7 and catalysis, 8 have made engineered nanomaterials (ENMs) an indispensable part of everyday life. As a consequence, scientific research has focused towards the synthesis and investigation of the properties of such ENMs in the form of nanofilms, [9][10][11] nanoparticles (NPs) 12 and nanomaterials in other promising forms, such as nanotubes. 13,14 The increased use and production of ENMs has led to an increasing exposure to such materials, especially in the form of NPs.…”

Reactions of ruthenium cyclopentadienyl precursor in the metal precursor pulse of Ru atomic layer deposition

“…18 To address this problem, non-oxidative reactants such as NH3 or H2 can be used to promote deposition of metal films. [20][21][22][23] The deposited Ru thin film is crystalline with hexagonal structure. The orientation is random at low temperature.…”