Dynamics and fragmentation mechanism of (C5H4CH3)Pt(CH3)3 on SiO2 surfaces

Kaliappan Muthukumar,Roser Valentí,Harald O Jeschke

doi:10.3762/bjnano.9.66

Abstract

The interaction of trimethyl(methylcyclopentadienyl)platinum(IV) ((C5H4CH3)Pt(CH3)3) molecules on fully and partially hydroxylated SiO2 surfaces, as well as the dynamics of this interaction were investigated using density functional theory (DFT) and finite temperature DFT-based molecular dynamics simulations. Fully and partially hydroxylated surfaces represent substrates before and after electron beam treatment and this study examines the role of electron beam pretreatment on the substrates in the initial stages of precursor dissociation and formation of Pt deposits. Our simulations show that on fully hydroxylated surfaces or untreated surfaces, the precursor molecules remain inactivated while we observe fragmentation of (C5H4CH3)Pt(CH3)3 on partially hydroxylated surfaces. The behavior of precursor molecules on the partially hydroxylated surfaces has been found to depend on the initial orientation of the molecule and the distribution of surface active sites. Based on the observations from the simulations and available experiments, we discuss possible dissociation channels of the precursor.

Highlights

Nanoscale device applications require a growth of regular or specially patterned transition metal nanodeposits
The interaction of (C5H4CH3)Pt(CH3)3 with the fully hydroxylated SiO2 substrate surfaces was investigated by placing the molecule with different orientations on several bonding sites and the most stable configuration is the one in which the methylcyclopentadienylring and two of the methyl groups that are directly bonded to Pt are oriented towards the substrate [14]
Two sets of (C5H4CH3)Pt(CH3)3 orientations were considered: (1) reclining orientations (Model1/1a and Model-2/2a), that differ in the orientation of the methylcyclopentadienyl ring of (C5H4CH3)Pt(CH3)3, and (2) upright configurations (Model-3/3a and Model-4/4a) in which either three of the methyl groups bonded to Pt or the centroid of the methylcyclopentadienyl ring bonds to the substrate

Summary

Introduction

Nanoscale device applications require a growth of regular or specially patterned transition metal nanodeposits. We have made a series of DFT studies in which we considered fully and partially hydroxylated SiO2 surfaces as a representative for untreated and electron beam pretreated substrates and investigated the adsorption [9,10] and dynamics of several carbonyl precursors [11]. In order to extend the knowledge on the adsorption and to address the open questions in the deposition process, in this study we use DFT and finite temperature DFT-based molecular dynamics (MD) simulations and investigate the adsorption behavior of (C5H4CH3)Pt(CH3)3 on fully and partially hydroxylated SiO2 surfaces.

Results

Conclusion