DEVICE AND METHOD FOR THE PRODUCTION OF SILICON BLOCKS
Device for the production of silicon blocks, the device comprising a vessel for receiving a silicon melt with a bottom, an inside, an outside and a central longitudinal axis and at least one support plate which is at least partially in direct contact with the bottom, and which forms a base together with the bottom, and means for generating an inhomogeneous temperature field on the inside of the bottom.
1 . A device for the production of silicon blocks, the device comprising
a. a vessel for receiving a silicon melt, the vessel comprising
i. a bottom;
ii. an inside;
iii. an outside; and
iv. a central longitudinal axis,
b. with the bottom
i. having an extension in a direction perpendicular to the central longitudinal axis; and
ii. along its extension in the direction perpendicular to the central longitudinal axis comprising at least two regions with different heat transfer coefficients.
2 . A device according to claim 1 , wherein the bottom has an inhomogeneous thickness, and wherein the bottom has a constant thermal conductivity.
3 . A device according to claim 2 , wherein the bottom comprises a multitude of recesses.
4 . A device according to claim 3 , wherein the recesses are provided on the outside of the bottom.
5 . A device according to claim 3 , wherein some of the recesses are arranged on the inside of the bottom and some of the recesses are arranged on the outside of the bottom.
6 . A device according to claim 5 , wherein the recesses on the inside of the bottom are arranged in the direction perpendicular to the central longitudinal axis offset to those on the outside.
7 . A device according to claim 3 , wherein the recesses have a depth in the range of 0.5 mm to 2 cm in the direction of the central longitudinal axis.
8 . A device according to claim 3 , wherein the recesses have an expansion in the range of 1 mm to 20 cm in the direction perpendicular to the central longitudinal axis.
9 . A method for the production of a device according to the invention, wherein in order to produce the vessel, a green body is produced in a first step.
10 . A method according to claim 9 , wherein the bottom of the vessel is structured by means of a punch before the green body has cured.
11 . A method according to claim 9 , wherein structuring of the bottom of the vessel takes place in an after-treatment step when the green body has cured.
12 . A device for the production of silicon blocks, the device comprising
a vessel for receiving a silicon melt, the vessel comprising
a bottom;
an inside;
an outside; and
a central longitudinal axis; and
at least one support plate
which is at least partially in direct contact with the bottom and
which forms a base together with the bottom; and
means for generating an inhomogeneous temperature field on the inside of the bottom.
13 . A device according to claim 12 , wherein the base has an inhomogeneous heat transfer coefficient.
14 . A device according to claim 12 , wherein the at least one support plate comprises at least two regions having different heat transfer coefficients.
15 . A device according to claim 12 , wherein the at least one support plate has an inhomogeneous thickness.
16 . A device according to claim 12 , wherein the bottom has an inhomogeneous thickness.
17 . A device according to claim 12 , wherein the support plate comprises a multitude of recesses.
18 . A device according to claim 12 , wherein the means for generating an inhomogeneous temperature field on the inside of the bottom comprise a cooling duct which can be acted upon by a coolant by means of at least one cooling device.
19 . A device according to claim 18 , wherein the cooling duct is arranged in the support plate in a meandering pattern.
20 . A device according to claim 18 , wherein a separate cooling circuit is provided for each recess.