Liquid-Solid Interface Morphologies and Defect Structures in Zone-Melting-Recrystallized Silicon-on-Insulator Films

摘要

In-situ optical microscopy has been used to observe liquid-solid interface morphologies during zone-melting recrystallization of silicon-on-insulator films. These morphologies have been correlated with the defect morphologies of the recrystallized films. Stable cellular solidification fronts, which are obtained at low zone velocities if the radiation intensity gradient in the interfacial region is small, yield subboundary free films. We suggest that under these experimental conditions the interface morphology is primarily the result of radiative heating rather than constitutional supercooling. We will focus on phenomenological descriptions of the solidification morphologies and the corresponding defect structures will be described. The dependence of these features on the upper-graphite-strip power and the zone velocity will be discussed. Samples consisted of 1-micrometer thick low-temperature (580 C), low-pressure chemical-vapor-deposited (LTLPCVD) amorphous Si on (100) Si wafers coated with 2 micrometers of thermally grown silicon dioxide. Keywords: Stable cellular solidification fronts, Reprints. (aw)