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US 2014/0030501 A1Published application
Apparatus and method for the production of ingots
AssigneeSolar World Industries America Inc.
InventorsNathan STODDARD, Wilfred Von AMMON
Life of this patent
Estimating the term…
Abstract
Apparatus and method for a crucible-less production of silicon ingots, wherein a support with a seed layer and a liquid layer is gradually lowered in a temperature field with a vertical gradient to solidify the liquid layer in a controlled way.
Claims20
An apparatus (1) for the production of ingots comprising
- a. a chamber (2) to provide a controllable atmosphere,
- i. wherein the chamber (2) has a top (3) and a bottom (4) spaced apart from each other in a longitudinal direction (5),
- b. a support (6) for supporting a seed layer (7),
- i. wherein the support (6) is movable in the longitudinal direction (5) relative to the chamber (5),
- c. at least one means (8, 9) for controlling a temperature field in a given volume of growth (Vg) in the chamber (2),
- i. wherein the temperature field has a temperature gradient in the longitudinal direction (5), and
- d. a feeding apparatus (10) for controllable feeding of material onto the seed layer (7).
4 more elements
A method for the production of ingots comprising the following steps
- providing an apparatus (1) with
- a chamber (2) to provide a controllable atmosphere,
- at least one means (8, 9) for controlling a temperature field with a temperature gradient in a longitudinal direction (5) in a given volume of growth (Vg) inside the chamber (2),
- a support (6) for a seed layer (7), the support being movable in the longitudinal direction (5) inside the chamber (2),
- and
- a controllable feeding apparatus (10) for providing feedstock,
- providing a seed layer (7) on the support (6), wherein the seed layer (7) defines a cross-sectional area of an ingot to be produced,
- moving the support (6), such that the seed layer (7) is located at a predetermined position within the volume of growth (Vg),
- generating a temperature field with a predetermined vertical temperature gradient within the volume of growth (Vg),
- providing feedstock on the seed layer (7) by way of the feeding apparatus (10),
- wherein the feeding of feedstock and the temperature field within the volume of growth (Vg) are controlled such that the entire seed layer (7) is covered with a layer (32) of liquid feedstock,
- lowering the support (6) while solidifying the layer (32) of liquid feedstock and
- adding more liquid feedstock from the feeding apparatus (10).
10 more elements
A wafer with a monocrystalline structure,
- wherein the wafer has a size of at least 140 mm×140 mm,
- wherein the wafer has a specific resistance, which in at least three quarters of a surface of the wafer has a variability of less than 5%, and
- wherein the wafer has a mean dislocation density over its surface which is less than 100/cm2.
Dependencies are inferred from the claim text.