Polycrystalline silicon ingot and polycrystalline silicon rod prepared from silicon materials purified according to physical method, and methods thereof

Abstract

The invention discloses a polycrystalline silicon ingot and a polycrystalline silicon rod prepared from silicon materials purified according to a physical method, and corresponding methods thereof. The silicon materials are prepared into the polycrystalline silicon ingot according to a directional solidification method; a first-type element and a second-type element are doped in the preparation process to control the resistivity of the polycrystalline silicon ingot within a preset range, wherein the first-type element controls the resistivity increase of the polycrystalline silicon ingot, andthe second-type element controls the resistivity reduction of the polycrystalline silicon ingot. According to the technical scheme, the polycrystalline silicon ingot is prepared by the directional solidification method to remove metal impurities, and accordingly, the metal impurities in the polycrystalline silicon ingot and the polycrystalline silicon rod can be removed effectively; through dopingof the first-type element and the second-type element, the doping balance in the polycrystalline silicon ingot and the polycrystalline silicon rod can be realized to control the resistivity within the preset range, so that the performance of silicon wafers prepared from the polycrystalline silicon ingot or the polycrystalline silicon rod is improved, and the cost of semiconductor structural devices is effectively reduced.

Description

technical field [0001] The invention relates to the technical field of semiconductors, more specifically, to a polycrystalline silicon ingot and a polycrystalline silicon rod prepared from silicon material purified by a physical method and a corresponding method. Background technique [0002] As the photovoltaic market matures, the competition becomes increasingly fierce, and the development volume of the industry rapidly expands. Under the premise that existing technologies cannot make rapid breakthroughs, it is an effective method to reduce the cost of photovoltaic production by reducing the cost of raw materials. For example, Reduce the cost of polysilicon material. Most of the silicon materials used in the solar energy industry are chemical methods. The silicon materials purified by the Siemens method can reach a purity of 6N-7N. However, the cost of chemically purified silicon materials is relatively high, which restricts the price of solar cells. Although the silicon ...

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Problems solved by technology

Most of the silicon materials used in the solar energy industry are chemical methods. The silicon materials purified by the Siemens method can reach a purity of 6N-7N. However, the cost of chemically purified silicon materials is relatively high, which restricts the price of solar cells.

Although the silicon material purified by physical method is relatively low in cost, its purity can only reach 4N-5N. The silicon material has many impurities and the impurities are mainly Al, Fe, Ti, Ca, B, P, etc. Silicon ingots prepared by ingot casting, crystal pulling process and physical purification of silicon materials, the metal impurities and non-metallic (B, P, etc.) impurities in it will lead to low performance of silicon wafers made from this silicon ingot

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