Continuous diffusion furnace and its ventilation method

Abstract

The invention provides a continuous diffusion furnace which comprises a furnace body with two open ends, a first air inlet pipe with an open end and an enclosed end, a second air inlet pipe with an open end and an enclosed end, and an exhaust pipe which is fixedly arranged on the inner wall of the furnace body chamber, wherein the first air inlet pipe is fixedly arranged on the inner wall of the furnace body chamber; the wall of the first air inlet pipe is uniformly provided with several small holes which are far from the inner wall of the furnace body chamber; the second air inlet pipe is fixedly arranged on the inner wall of the furnace body chamber; the wall of the second air inlet pipe is uniformly provided with several small holes which are far from the inner wall of the furnace body chamber; two ends of the exhaust pipe are both opened; negative pressure is applied on the two ends of the exhaust pipe; and the wall of the exhaust pipe is provided with several small holes which are far from the inner wall of the furnace body chamber. By the adoption of the ventilation method of the continuous diffusion furnace, consistent density of reactant gases around silicon chips in the same batch is realized. PN junctions of the silicon chips are uniform. And two breather pipes are simultaneously used for ventilation, so as to avoid obstruction of breather pipe holes.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a continuous diffusion furnace and a ventilation method thereof. Background technique [0002] In the production process of crystalline silicon solar cells, diffusion is an important process for preparing PN junctions. The existing technology uses a high-temperature closed-tube diffusion furnace to complete this process. Diffusion technology is an important process in monocrystalline silicon and polycrystalline silicon solar cells. Its purpose is to form the emitter region with the opposite conductivity type of the substrate, thereby forming a PN junction. Usually monocrystalline silicon and polycrystalline silicon solar cells use P-type substrates, phosphorus oxychloride liquid source diffusion, and a diffuse N-type emitter region is formed through a series of chemical reactions and phosphorus atom diffusion processes. The diffusion process of solar cells re...

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Problems solved by technology

[0004] The object of the present invention is to provide a continuous diffusion furnace and its ventilation method to solve the problems of uneven distribution of the gas field in the diffusion furnace and easy blockage of the inlet pipe

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