Method for producing silicon-ingots (1) including the following steps: providing a silicon melt (3), growing a block (2) of silicon from the silicon melt (3), the block (2) having a predetermined crystal orientation, cutting the block (2) along at least one cutting plane (16, 17, 18) into a number of silicon-ingots (1).

Method for producing silicon-ingots (1) including the following steps: providing a silicon melt (3), growing a block (2) of silicon from the silicon melt (3), the block (2) having a predetermined crystal orientation, cutting the block (2) along at least one cutting plane (16, 17, 18) into a number of silicon-ingots (1).

Semi-conductor wafers with thin and thicker regions at controlled locations may be for Photovoltaics. The interior may be less than 180 microns or thinner, to 50 microns, with a thicker portion, at 180-250 microns. Thin wafers have higher efficiency. A thicker perimeter provides handling strength. Thicker stripes, landings and islands are for metallization coupling. Wafers may be made directly from a melt upon a template with regions of different heat extraction propensity arranged to correspond to locations of relative thicknesses. Interstitial oxygen is less than 610.sup.17 atoms/cc, preferably less than 210.sup.17, total oxygen less than 8.7510.sup.17 atoms/cc, preferably less than 5.2510.sup.17. Thicker regions form adjacent template regions having relatively higher heat extraction propensity; thinner regions adjacent regions with lesser extraction propensity. Thicker template regions have higher extraction propensity. Functional materials upon the template also have differing extraction propensities.

Semi-conductor wafers with thin and thicker regions at controlled locations may be for Photovoltaics. The interior may be less than 180 microns or thinner, to 50 microns, with a thicker portion, at 180-250 microns. Thin wafers have higher efficiency. A thicker perimeter provides handling strength. Thicker stripes, landings and islands are for metallization coupling. Wafers may be made directly from a melt upon a template with regions of different heat extraction propensity arranged to correspond to locations of relative thicknesses. Interstitial oxygen is less than 610.sup.17 atoms/cc, preferably less than 210.sup.17, total oxygen less than 8.7510.sup.17 atoms/cc, preferably less than 5.2510.sup.17. Thicker regions form adjacent template regions having relatively higher heat extraction propensity; thinner regions adjacent regions with lesser extraction propensity. Thicker template regions have higher extraction propensity. Functional materials upon the template also have differing extraction propensities.

Disclosed is a preparation method of a polycrystalline silicon ingot. The preparation method comprises: providing a silicon nucleation layer at the bottom of a crucible, and filling a silicon material above the silicon nucleation layer; heating the silicon material to melt same, adjusting the thermal field inside the crucible to make the melted silicon material to start crystallization on the basis of the silicon nucleation layer; and when the crystallization is finished, performing annealing and cooling to obtain a polycrystalline silicon ingot. By adopting the preparation method, a desirable initial nucleus can be obtained for a polycrystalline silicon ingot, so as to reduce dislocation multiplication during the growth of the polycrystalline silicon ingot. Further disclosed are a polycrystalline silicon ingot obtained through the preparation method and a polycrystalline silicon wafer made using the polycrystalline silicon ingot as a raw material.

Disclosed is a preparation method of a polycrystalline silicon ingot. The preparation method comprises: providing a silicon nucleation layer at the bottom of a crucible, and filling a silicon material above the silicon nucleation layer; heating the silicon material to melt same, adjusting the thermal field inside the crucible to make the melted silicon material to start crystallization on the basis of the silicon nucleation layer; and when the crystallization is finished, performing annealing and cooling to obtain a polycrystalline silicon ingot. By adopting the preparation method, a desirable initial nucleus can be obtained for a polycrystalline silicon ingot, so as to reduce dislocation multiplication during the growth of the polycrystalline silicon ingot. Further disclosed are a polycrystalline silicon ingot obtained through the preparation method and a polycrystalline silicon wafer made using the polycrystalline silicon ingot as a raw material.

A heater comprises a plurality of zones with at least two zones having a variable power density gradient different from one another. The heater having zones of different variable power density gradients allows for controlling the heat output and temperature profile of the heater in one or more directions of the heater. The heater can be used, for example, to control the temperature profile in a vertical direction.

A heater comprises a plurality of zones with at least two zones having a variable power density gradient different from one another. The heater having zones of different variable power density gradients allows for controlling the heat output and temperature profile of the heater in one or more directions of the heater. The heater can be used, for example, to control the temperature profile in a vertical direction.

An investment casting apparatus includes a furnace having an opening, a mold support, and a multi-axis actuator connected with the mold support and configured to retract the mold support from the opening with multiple-axis motion. An investment casting method includes withdrawing, with multiple-axis motion, a mold through the opening of the furnace to solidify a molten metal- or metalloid-based material in the mold. The apparatus and method can be used to form a cast article that has a body formed of the metal- or metalloid-based material. The body has a multi-textured, single crystal microstructure.

An investment casting apparatus includes a furnace having an opening, a mold support, and a multi-axis actuator connected with the mold support and configured to retract the mold support from the opening with multiple-axis motion. An investment casting method includes withdrawing, with multiple-axis motion, a mold through the opening of the furnace to solidify a molten metal- or metalloid-based material in the mold. The apparatus and method can be used to form a cast article that has a body formed of the metal- or metalloid-based material. The body has a multi-textured, single crystal microstructure.