Transient nucleation and manipulation of nucleation sites in solid‐state crystallization ofa‐Si films

Autor: Takao Yonehara, Hideya Kumomi
Rok vydání: 1994
Předmět:
Zdroj: Journal of Applied Physics. 75:2884-2901
ISSN: 1089-7550
0021-8979
DOI: 10.1063/1.356182
Popis: Solid‐state nucleation of Si crystals in a‐Si films is controlled by Si ion implantation prior to the isothermal annealing. The process of the nucleation includes a long transient period that causes the diminishing shape of the grain size distribution (GSD). The parameters appearing in the kinetic theory of transient nucleation are estimated from the GSD in a‐Si. It is found that the ion implantation reduces the steady‐state nucleation rate and elongates the time lag, while the growth rate is almost constant. The dependence of the above parameters is simulated based on the model of heterogeneous nucleation. It is qualitatively suggested that the suppression of the nucleation can be attributed to the modification of the interface to the SiO2 underlayer such as the changes in the self‐diffusion or in the interfacial energy. When the nucleation rate is spatially controlled in the plane of the film, a small portion provides the artificial nucleation site. If the sites are periodically placed, the GSD shrinks ...
Databáze: OpenAIRE