The interaction of cavities in silicon with moving amorphous–crystalline interfaces

A detailed transmission electron microscopy (TEM) study has been carried out on the effect on helium-filled cavities (bubbles), contained entirely within a buried amorphous layer in silicon, of the recrystallisation of the layer by solid-phase epitaxial growth. On annealing to temperatures in the range 550–600 °C, recrystallisation took place at both amorphous–crystalline interfaces which, as they moved, were observed to sweep the cavities, keeping them initially confined within the amorphous region. The recrystallisation also gave rise to the formation of microtwin lamellae which clearly did not nucleate on the bubbles; contrary to previous reports. This paper seeks to explain aspects of the interaction of both cavities and microtwins with the advancing a/c interface in terms of defects within the amorphous layer.