CN201183847Y - Thermal field structure of a polysilicon ingot furnace with a layer of insulation strips - Google Patents

Abstract

The utility model relates to equipment in a polysilicon ingot casting furnace, in particular to a thermal field structure of a polysilicon ingot casting furnace with a layer of thermal insulation strips, which includes a thermal insulation cage installed on the side and the top of the thermal insulation cage. The heater on the surface, the graphite cooling block for the crucible, and a layer of insulation strips are arranged around the inner cavity of the heat insulation cage. This layer of insulation strips forms an insulation belt with a height h of 73-83mm and a width b of 77-87mm. . Through the test, compared with the original three-layer insulation strips stacked up and down in the thermal insulation cage, the solid-liquid interface of its crystal growth is concave, and the growth rate of the surrounding crystals is faster than that of the middle crystals. In the effective area The crystallite content is reduced, so that the amount of crystallite in the produced crystal ingot is reduced.

Description

Thermal field structure of a polysilicon ingot furnace with a layer of insulation strips

technical field

The utility model relates to equipment in a polysilicon ingot furnace, in particular to a thermal field structure of a polysilicon ingot furnace with a layer of insulation strips.

Background technique

During the growth of polysilicon, due to the instability of the thermal field, microcrystals will be generated inside the crystal. When the thermal field of the DSS450 polycrystalline casting furnace does not change, the content of microcrystals in each ingot produced reaches 49.9% %, so the yield rate of the final product will be greatly reduced. The growth direction of the crystal is from the bottom to the top. The function of the insulation strip is to prevent the temperature around the crystal block from cooling too quickly, so that the crystal grows vertically, and prevents the crystal from crystallizing before it is fully grown, thereby producing microcrystals. The original DSS450 polysilicon casting furnace had three insulating strips, so that the crystals would crystallize halfway through the growth, and the crystallized solid-liquid interface was horizontal, and this method was the least ideal.

Utility model content

In order to overcome the problem that the crystal ingot produced by the existing polysilicon ingot furnace has too high a crystallite ratio and affects product quality, the utility model provides a thermal field of a polysilicon ingot furnace with excellent crystal quality and a layer of insulation strips structure.

The technical scheme adopted by the utility model is: a thermal field structure of a polysilicon ingot furnace with a layer of thermal insulation strips, including a thermal insulation cage body, a heater installed on the side and top surface of the thermal insulation cage body, and a The graphite cooling block of the crucible and the successively stacked insulation belts arranged around the inner cavity of the thermal insulation cage, the height h of the insulation belt is 73-83mm, the width b is 77-87mm, and consists of a layer of insulation strips.

There are three layers of insulation strips stacked up and down in the original thermal insulation cage, and now two layers have been subtracted. After subtracting two layers of insulation layers, the solid-liquid interface of its crystal growth is concave, which reduces the amount of crystallites in the produced crystal ingot.

The beneficial effects of the utility model are: through the test, compared with the three-layer insulation strips stacked up and down in the original thermal insulation cage, the solid-liquid interface of its crystal growth is concave, and the growth rate of the surrounding crystals is faster than In the middle of the crystallization, the crystallite content in the active area is reduced, so that the amount of crystallites in the produced boule is reduced.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

Fig. 1 is a structural representation of the utility model.

In the figure: 1. Thermal insulation cage body, 2. Heater, 3. Graphite cooling block, 4. Thermal insulation strip.

Detailed ways

A kind of thermal field structure of the polysilicon ingot casting furnace with one layer of thermal insulation bar as shown in Figure 1, comprises the thermal insulation cage body 1, the heater 2 that is installed on the side and the top surface in the thermal insulation cage body 1, places The graphite cooling block 3 of the crucible is provided with a layer of insulation strip 4 around the inner cavity of the heat insulation cage body 1, and this layer of insulation strip 4 forms a high h that is 73-83mm, and a width b that is 77-87mm.

In the DSS450 polysilicon ingot casting furnace, the thermal insulation bar 4 in the thermal insulation cage body 1 originally had three layers, and now the upper two layers are subtracted. Put the silicon raw material into the crucible, and the crucible rests on the graphite cooling block 3. The bottom and surrounding of the crucible are lined with protective plates, and the top has a cover plate. When melting the silicon material, the thermal insulation cage 1 and the graphite cooling block 3 are closed A thermal field chamber for heating the silicon raw material in the crucible is formed. When the melted silicon liquid cools and crystallizes, the thermal insulation bar 4 in the thermal insulation cage 1 makes the crystal growth around the silicon liquid slower than the crystal in the middle, and the crystal grows in a concave shape, and the content of microcrystals in the effective area decreases, making The content of crystallites in the out-going ingot is reduced from the current 49.9% to 6.2%.

Claims (2)

1. A thermal field structure of a polysilicon ingot furnace with a layer of thermal insulation strips, including a thermal insulation cage (1), a heater (2) installed on the side and top of the thermal insulation cage (1) , the graphite cooling block (3) for placing the crucible and the successively stacked thermal insulation belts arranged around the inner cavity of the thermal insulation cage (1), it is characterized in that: in the inner cavity of the thermal insulation cage (1) The height h of the insulation belt arranged around is 73-83mm, and the width b is 77-87mm. 2. The thermal field structure of a polysilicon ingot casting furnace with a layer of insulation strips according to claim 1, characterized in that: the insulation strip is composed of a layer of insulation strips (4).

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