Superheat of silicon crystals observed by live X-ray topography

Abstract

Abstract:In-situ observations of Si crystal growth and melting have been carried out by live X-ray diffraction topography. Superheated solid states beyond the melting point was observed for dislocation-free crystals with melting in their inside. Dislocations were found to impede superheat and to melt the crystal without an appreciable superheating. A slightly superheated state accompanying melting removes all dislocations including immobile ones by their climb motion. It is proposed that self-interstitials needed for the volume change by melting are supplied by climb of dislocations, in contrast to dislocation-free crystals creating the interstitials thermally. In real crystal growth, remelting occurs naturally by melt convection and acts to make the growing crystal dislocation-free.

Intrinsic point defect behavior in silicon crystals during growth from the melt: A model derived from experimental results

“…growth interface is always filled with vacancies [9][10][11] and II. interstitial atoms are generated when the thermal gradient is larger than a certain value (critical thermal stress) [9,11,12].…”

Real‐time X‐ray diffraction imaging for semiconductor wafer metrology and high temperature in situ experiments

“…At the same time, X-ray diffraction topography was successfully performed by employing hard X-ray synchrotron radiation [5]. The first experiments combining synchrotron radiation and live topography were reported in the 1980s by Tuomi et al [6], over which period Chikawa continued to improve his system with a conventional source [7].…”