Method of solidifying a semiconductor by adding a doped semiconductor charge during crystallization

摘要

The process comprises forming a bath (103) of molten semiconductor from a first charge of semiconductor comprising the dopants, and solidifying the molten semiconductor by melting additional charges of semiconductor and then adding to the molten bath under solid form. The solidification of the semiconductor lowers the variability of the molten bath according to the ratio of the predetermined variability factors as given in the specification. The dopants include electron acceptors with boron atoms and electron donors with phosphor atoms. The process comprises forming a bath (103) of molten semiconductor from a first charge of semiconductor comprising the dopants, and solidifying the molten semiconductor by melting additional charges of semiconductor and then adding to the molten bath under solid form. The solidification of the semiconductor lowers the variability of the molten bath according to the ratio of the predetermined variability factors as given in the specification. The dopants include electron acceptors with boron atoms and electron donors with phosphor atoms. The additional charges are added to the molten bath with high crystallization speed and low addition speed and according to an equation as given in the specification. A charge of semiconductor is added to the mass of solidified semiconductor each time to increase 1% of mass compared to the total mass of solidified semiconductor obtained at the end of solidification process. The solidification is carried out in a Bridgman type furnace. The furnace comprises a closed enclosure, and a crucible (102) under argon atmosphere. The bath is disposed in the crucible of the furnace. The addition of semiconductor charges is carried out using a dispensing device connected to a preheater. The time for the addition of additional charges is determined using a unit for controlling the dispensing device. The concentration of the dopants in the first charge of semiconductor is different from the same type of dopants in additional charges of semiconductor.