Apparatus for producing zonal polycrystalline silicon by edge limited silicon film growth method

Abstract

The invention discloses a device for producing strip polysilicon by an edge limiting silicon film growing method. The device comprises a tapered guider with a central sleeve and an upper layer structure supported on the top surface of the tapered guider; the upper layer structure comprises an inner sleeve set in coaxial arrangement with the central sleeve, an outer sleeve set coaxially arranged in the periphery of the inner sleeve set, and a top slab for sealing the top parts of the inner sleeve set and the outer sleeve set; the bottom edge of the inner sleeve set is provided with a pluralityof supporting legs and is supported on the top surface of the tapered guider through the supporting legs; and a feed discharge passage is formed between the adjacent supporting legs. The device mainly reconstructs the upper layer structure aiming at the prior art; the outer sleeve with function of heat shield is vertically arranged, has high radial temperature gradient and can form a thermal field favorable for the growth of crystal; and the design of the inner sleeve and the feed discharge passage can achieve the functions of speed reduction and guidance so as to reduce the splashing of the silicon solution when silicon particles fall into a silicon solution, and solve the problem that mushroom-shaped feed agglomerates interrupt the growth of the strip silicon.

Description

technical field [0001] The invention relates to a device for producing polysilicon, in particular to a device for producing band-shaped polysilicon by edge-limited silicon film growth method. Background technique [0002] Silicon crystals are the most commonly used materials in the semiconductor and solar industries. Ribbon-shaped polysilicon is a kind of polysilicon raw material that is shaped into thin slices, because when it is processed into silicon wafers, the knife loss (kerf loss) is very small, so the utilization rate of the material is improved to the greatest extent. [0003] The edge-defined silicon film growth method (EFG method) is well known as a method of growing ribbon-shaped silicon. For example, Chinese invention patent 91104726.3 describes the equipment and the wet-tip guided mode used in the edge-defined silicon film growth method. In Chinese invention patents 90109365.3, 91101558.2 and 90104389.3, the control mode of the edge-limited silicon film growt...

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Problems solved by technology

In addition, in this solution, the structure of the annular discharge channel is complicated, especially the umbrella-shaped underframe in the upper structure of the channel, because the wall is thin and the shape is complex, high processing accuracy and high-quality high-temperature-resistant graphite parts are required in manufacturing , which increases the difficulty of production and increases the cost

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