The heat treatments performed during the metallization of GaAs results in a complex sequence of diffusion induced transformations. During the process, the continuity of the Au film breaks down and islands with a wide size distribution are formed. The reaction at the Au/GaAs interface is coupled with the partial decomposition of the GaAs matrix, the formation of liquid phase alloy, and the release of As in the gas phase. In order to understand the sequence of reactions in this system, one must consider the interaction of gas, liquid and solid phases simultaneously. We have performed a set of experiments in closed and open gas phase systems and analyzed the resulting morphologies and phases. Cross sectional TEM analysis was performed simultaneously with the study of surface morphologies using SEM, and composition distribution determination with EDS and SIMS. In this system, it is not possible to describe the diffusion process with the usual one dimensional model, which assumes the homogeneity of the sample perpendicular to the diffusion front.
|Number of pages||6|
|Journal||Defect and Diffusion Forum|
|Issue number||PART 2|
|Publication status||Published - 2005|
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics