AVS 51st International Symposium
    Electronic Materials and Processing Tuesday Sessions
       Session DI+PS-TuM

Paper DI+PS-TuM4
DFT Study of the Initial ALD Reactions of Hf(N(CH3)2)4 on the SiO2 and Si-H Surfaces: Mechanism, Kinetics, Vibrational Spectra and Interface Structure

Tuesday, November 16, 2004, 9:20 am, Room 304C

Session: High-k Dielectrics: Growth and Processing
Presenter: C.B. Musgrave, Stanford University
Authors: J.G. Han, Stanford University
C.B. Musgrave, Stanford University
M.J. Kelley, North Carolina State University
G.N. Parsons, North Carolina State University
Correspondent: Click to Email
Atomic layer deposition is ideally capable of depositing uniform thin films of materials one atomic layer at a time. In practice, the initial coverage of active sites on the starting substrate determines the initial growth rate, which is typically below the steady state growth rate. Furthermore, the initial reactions on the starting substrate are important in defining the atomic structure of the interface between the deposited film and the substrate. Because the electronic properties of advanced CMOS are highly sensitive to the electronic structure and thus the atomic structure of this interface, it is essential to gain control over the structure of the interface through the chemistry of the ALD process on the starting substrate. We have used ab initio electronic structure theory to calculate mechanisms leading to various interface structures for the reaction of a tetrakis(dimethylamido) hafnium precursor with Si-H and Si-OH terminated substrates and the resulting interface bonding. We also calculate the vibrational spectra for some possible surface species and compare these with those measured by FTIR. Our calculations show that the adsorbed metal precursor activates neighboring Si-H sites enabling subsequent reactions with water and the ALD metal precursor.