In Situ Transmission Electron Microscopy Observation of Single Crystallization of Filled Aluminum Interconnection

Abstract
In situ transmission electron microscopy (TEM) observation was carried out to clarify the aluminum single-crystallization mechanism. Aluminum filling into the grooves formed on an amorphous insulator completed at 903 K, which was 30 K below the melting point of pure aluminum. It was found that aluminum remained in the liquid state even at temperatures more than 80 K below its melting point. It is concluded that this supercooled aluminum state is essential to the fabrication of single-crystal aluminum lines, because this state enables fast solidification and suppresses polynucleations.