PROCEDE DE PREPARATION DE SILICIUM A L'ETAT SOLIDE

摘要

The present invention relates to a method for preparing solid-state silicon (11) supported by a layer (40) of fractured silicon carbide comprising at least the steps of: d) providing a mould (1) in which at least one recess (2) is arranged, defined by walls (3) intended for forming a support for moulding silicon (10) in molten state; e) placing said walls (3) in contact with silicon (10) in molten state; and f) subjecting said silicon (10) in molten state to conditions that are favourable for the solidification thereof in said recess (2), said method being characterised in that the inner surface (4) of said walls (3) is made of a graphite intended for being placed in contact with the silicon (10) in molten state and having a thermal expansion coefficient alphaGr complying, in a temperature range from ambient temperature to the melting temperature of silicon, with the following equation: 0.8 alphaSi <= alphaGr <= alphaSi + 0.7 (alphaSiC - alphaSi), where alphaSi denotes the thermal expansion coefficient of the silicon and alphaSiC denotes the thermal expansion coefficient of the silicon carbide.