GE NANOCRYSTALS WITH A SHARP SIZE DISTRIBUTION - A DETAILED STUDY OF THE CRYSTALLIZATION OF A-SI1-XOXGEY ALLOY-FILMS

Thin amorphous Si1-xOxGey alloy films were prepared by de magnetron sp uttering. We found that the as-prepared films contain amorphous Ge clu sters with small size distributions. A low Ge content of the films is connected with very small Ge clusters in the as-prepared films and wit h regions where Ge atoms are densely spread in the matrix. Films with a larger Ge content show an increasing number of larger clusters. Thes e clusters are closed together, thus producing dimeres and trimeres. D ifferent annealing procedures resulted in different modes of crystalli zation. A crystallization of the as-prepared clusters is found after a n annealing process with crystal diameters slightly greater than the c luster size. With annealing step by step inside the diffraction system we demonstrated the growth process including the final recrystallizat ion of the aggregates.