A Silicon Wafer Primary Negative Pressure Diffusion Process

Abstract

The invention provides a negative pressure diffusion process for silicon wafers, which comprises the following steps: performing pre-diffusion treatment on double-sided thinned silicon wafers, printing diffusion sources on the treated silicon wafers, and using screen printing technology to process the treated silicon wafers One side of the silicon wafer is printed with a phosphorus diffusion source, and the other side is printed with a boron diffusion source or a boron-aluminum diffusion source; the sides of the same diffusion source of the silicon wafer are stacked and loaded into a boat; low-pressure diffusion is performed in a diffusion furnace and post-diffusion treatment is performed. The beneficial effect of the present invention is that the phosphorus diffusion source, the boron diffusion source or the boron aluminum diffusion source are respectively printed on both sides of the silicon wafer by the screen printing process, so that the coating process of the silicon wafer liquid source is simplified and the processing cycle is shortened; the liquid source After coating, a negative pressure diffusion process is adopted to reduce the source return at the edge of the silicon wafer, and the diffusion process steps are simplified to improve the diffusion efficiency; this process method is used to perform a single diffusion of the liquid source of the silicon wafer, so that the produced PN junction is uniform, making The processing cost of silicon wafer is reduced.

Description

technical field [0001] The invention belongs to the field of silicon wafer manufacturing technology, in particular to a silicon wafer primary negative pressure diffusion process. Background technique [0002] With the development of semiconductor technology, the requirements for passivation of semiconductor surfaces are getting higher and higher. As a passivation material, it should have good electrical properties, reliability, good chemical stability, operability and economy. According to the above requirements, special glass for semiconductor passivation has been applied in the semiconductor industry as an ideal semiconductor passivation material. Chips made of special glass for semiconductor passivation are called glass passivation process chips (GPP chips). [0003] At present, most of the production of silicon wafers in the industry will use the diffusion process to form a PN junction. At present, the commonly used diffusion process in the industry generally uses one f...

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Problems solved by technology

[0003] At present, most of the production of silicon wafers in the industry will use the diffusion process to form a PN junction. At present, the commonly used diffusion process in the industry generally uses one full diffusion of phosphorus paper source and boron paper source or two diffusion methods of phosphorus and boron. These diffusion methods have Unavoidable defects: 1) Since the gap between the silicon wafers increases after the paper source is sintered, the volatilized phosphorus source diffuses to the boron surface and causes return to the source; Sandblasting or chemical thinning is required on one side to remove the anti-source amount, and then boron diffusion is performed, which is costly, low in diffusion efficiency, and prone to fragmentation

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