Process and apparatus for manufacturing polycrystalline silicon ingots

The present application describes a process and apparatus for producing polycrystalline silicon ingots. During the process, a crucible is arranged in a process chamber, wherein the crucible is filled with solid silicon material or is being filled with silicon material in the process chamber. The crucible is located with respect to at least one diagonal heater in such a way that the diagonal heater is located laterally offset to and generally above the silicon ingot to be produced. Thereafter, the solid silicon material in the crucible is heated above the melting temperature of the silicon material in order to form molten silicon in the crucible, and thereafter, the silicon material in the crucible is cooled down below the solidification temperature of the molten silicon, therein a temperature profile in the silicon material during the cooling phase is controlled at least partially via the at least one diagonal heater. The apparatus comprises a process chamber, a crucible holder inside the process chamber, and