Comment on 'Intrinsic point defect incorporation in silicon single crystals grown from a melt, revisited' [J. Appl. Phys. 110, 063519 (2011)]

摘要

Silicon is a material remarkable for the coexistence of vacancies (V) and self-interstitials (I) with comparable equilibrium concentrations. During crystal growth, after mutual annihilation upon lowering the temperature, only one of the defects, either V or I, becomes dominant in the crystal bulk (in other words-becomes incorporated into the crystal). These point defects give rise to aggregates known as "grown-in microdefects" which are of crucial importance for the quality of silicon materials. The type of the dominant incorporated defect was shown to be determined by the ratio of the growth rate V and the axial temperature gradient G defined in the vicinity of the crystal-melt interface. If V/G exceeds a certain critical value (V/G)_(cr), then the incorporated defects are vacancies and they give rise to voids. If V/G is below this critical value, then the incorporated defects are self-interstitials and they give rise to intrinsic dislocation loops. This V/G rule is valid for both Czochralski-grown (CZ) and float-zoned (FZ) crystals.