CN201183846Y - Thermal field structure of polycrystalline silicon casting furnace - Google Patents

Abstract

The utility model relates to a device in a polycrystalline silicon ingot furnace, in particular to a thermal field structure of a polycrystalline silicon ingot furnace. The thermal field structure comprises an insulated cage body and a graphite cooling block for placing a crucible. Only heaters for heating silicon material are installed in the insulated cage body, and the heaters are respectively installed on the side and the top surfaces of the cavity of the insulated cage body. Through experiments, compared with the three layers of heat preservation bars lapped up and down in the original insulated cage body, the solid-liquid interface for the growth of the crystal thereof is concave, the growth speed of the peripheral crystal is faster than that of the crystal in the middle, the crystallite content in the effective area is reduced, so that the crystallite amount produced in the crystal ingot decreases.

Description

The thermal field structure of polycrystalline silicon ingot or purifying furnace

Technical field

The utility model relates to the thermal field structure of equipment, particularly a kind of polycrystalline silicon ingot or purifying furnace in a kind of polycrystalline silicon ingot or purifying furnace.

Background technology

Polysilicon is in the process of growth, because the instability of thermal field can produce crystallite at crystals, at DSS450 polycrystalline foundry furnace thermal field under the situation about not changing, content of crystallite reaches 49.9% in each crystal ingot that comes out, and the good article rate of the finished product will reduce greatly like this.The crystalline direction of growth is from bottom to top, and the effect of insulation bar is to make the temperature around the crystal block can refrigerative too not fast, makes the crystal vertical-growth, prevents that crystal from not grow with regard to crystallization, thus the generation crystallite.The insulation bar of original DSS450 polycrystalline foundry furnace is 3, the synoptic diagram of thermal field structure as shown in Figure 2, with regard to crystallization, the crystalline solid-liquid interface is horizontal when growing into half for crystal like this, and this mode is an ideal least.

The utility model content

Too high for the crystallite ratio that overcomes the crystal ingot that existing polycrystalline silicon ingot or purifying furnace produces, influence the deficiency of quality product, the utility model provides a kind of thermal field structure of polycrystalline silicon ingot or purifying furnace of crystalline quality excellence.

The technical scheme that the utility model adopted is: a kind of thermal field structure of polycrystalline silicon ingot or purifying furnace, comprise heat insulating cage body, place the graphite cooling block of crucible, the well heater of heating silicon materials only is installed in heat insulating cage body, and well heater is installed in respectively on the side and end face of heat insulating cage intracoelomic cavity.

The insulation bar that three layers of stacked on top of one another are arranged in original heat insulating cage body, after all removing now, the solid-liquid interface that its crystalline is grown up is rendered as matrix, makes that the crystallite amount in the crystal ingot of producing descends.

The beneficial effects of the utility model are: by test, compare with three layers of insulation bar that stacked on top of one another is set in the original heat insulating cage body, the solid-liquid interface that its crystalline is grown up is rendered as matrix, crystalline growth rate on every side is faster than the intermediary crystallization, content of crystallite in the effective area reduces, and makes that the crystallite amount in the crystal ingot of producing descends.

Description of drawings

Below in conjunction with drawings and Examples the utility model is further specified.

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

Fig. 2 is the synoptic diagram of the thermal field structure of original polycrystalline silicon ingot or purifying furnace

Among the figure: 1. heat insulating cage body, 2. well heater, 3. graphite cooling block, 4. insulation bar.

Embodiment

The thermal field structure of a kind of polycrystalline silicon ingot or purifying furnace as shown in Figure 1, the graphite cooling block 3 that comprises heat insulating cage body 1 and placement crucible, the well heater 2 of heating silicon materials only is installed in heat insulating cage body 1, and well heater 2 is installed in respectively on the side and end face of heat insulating cage body 1 inner chamber.

In the DSS450 polycrystalline silicon ingot or purifying furnace, the insulation bar 4 in the heat insulating cage body 1 had three layers originally, all removed now.The silicon raw material is joined in the crucible, and crucible is put and is placed on the graphite cooling block 3, crucible bottom and be lined with backplate all around, and the top has cover plate, and when dissolving silicon materials, heat insulating cage body 1 and graphite cooling block 3 close up the thermal field chamber that forms silicon raw material in the heating crucible.Silicon liquid cooling after dissolving is but during crystallization, owing to there has not been previous insulation bar 4, make the crystal growth around the silicon liquid be slower than the intermediary crystallization, crystal is the spill growth, the content of crystallite reduces in the effective area, and the content that makes the crystallite in the crystal ingot that draws is for dropping to 19.5% from present 49.9%.

Claims (1)

1, a kind of thermal field structure of polycrystalline silicon ingot or purifying furnace, the graphite cooling block (3) that comprises heat insulating cage body (1) and placement crucible is characterized in that: the well heater (2) of heating silicon materials only is installed in described heat insulating cage body (1), and well heater (2) is installed in respectively on the side and end face of heat insulating cage body (1) inner chamber.

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