TRANSIENT KINETICS IN SOLID-PHASE EPITAXY OF NI DOPED AMORPHOUS-SILICON

Solid phase epitaxy (SPE) of amorphous silicon layers doped with Ni in the concentration range 10(19)-10(20) Cm-3 has been studied. The amor phous layers were produced by self-ion implantation of Si(100) samples . Transient kinetics of the SPE process are observed, and the results imply that the regrowth changes from an initial impurity driven crysta llization to the 'ordinary' thermally activated one. The initial enhan cement of the SPE rate may be attributed to a difference in the densit y of trapping sites for Ni atoms at the initial ('as-prepared') amorph ous-crystalline (a-c) interface compared to the advancing one. The rol e of the simultaneous process of Ni precipitation is also addressed. T he results are consistent with those SPE models which treat rearrangem ents at the a-c interface as a critical stage in the crystallization p rocess.