Kinetics of the formation of an amorphous layer during a solid state reaction
Abstract (Summary)Solid state reaction as a new method of amorphous film fabrication was introduced by R. Schwartz and W. L. Johnson in 1983. A thermodynamic explanation for the process given by the original article provides a clue to understanding the forces making the reaction possible. This thesis emphasizes the kinetic approach to the description of the reaction. The movements of the interfaces as a fundamental mechanism of the reaction is suggested. The reaction in La-Au and Ni-Hf multilayers is described. Resistance measurements, TEM and SIMS techniques, and Rutherford backscattering are used to study the process. The thesis contains a proof that the final product of the solid state reaction is amorphous. It describes the morphology of the reacting multilayers. The one-dimensional and multi-dimensional processes taking place during the growth are separated. The thesis connects the properties of the reaction with known properties of the "fast diffusion." The phenomenological model for the reaction is introduced. The model consists of a diffusion equation with a new set of boundary conditions. The amorphous layer growth rate in the limit of short time is found to be X=1-exp(-At) and X=-1/(A-1)+(2at)1/2 in the limit of long time. The "steady state" approximation as a solution to the diffusion equations in the limit of long time is found to be incorrect. The model shows excellent agreement with the experimental data.
Advisor:William Lewis Johnson
School Location:USA - California
Source Type:Master's Thesis
Date of Publication:06/11/1984