VERTICAL GRADIENT FREEZE METHOD FOR PRODUCING CRYSTALS

摘要

The invention relates to a method for producing a monocrystalline, quasi-monocrystalline or multicrystalline metal or semi-metal body, particularly monocrystalline, quasi-monocrystalline or multicrystalline silicon bodies, by oriented solidification from a melt 3 according to the vertical gradient freeze method (VGF method). In the method, the melt solidifies in a melt crucible 2 into the monocrystalline, quasi-monocrystalline or multicrystalline metal or semi-metal body in an oriented manner under the effect of a temperature gradient extending vertically and from the upper end of the melt crucible 2 to the lower end of said melt crucible 2. Before introduction of the melt 3 into or production of the melt 3 in the melt crucible 2, the bottom of the melt crucible is covered with a thin separation layer 35, 36. According to the invention, the thin separation layer 35, 36 is formed of quartz glass, particularly of highly pure, also synthetically produced, quartz glass. The ingots produced in this manner have very homogeneous properties over their entire volume and have a very low impurity content even in the peripheral areas.