A Diffusion Technology of Liquid Source Before Silicon Wafer Glass Passivation

Abstract

The invention provides a liquid source diffusion process before glass passivation of silicon wafers, which includes the following steps: put the double-sided thinned silicon wafers into the silicon wafers for pre-diffusion treatment, print the diffusion sources on the treated silicon wafers, and use screen printing technology to process The final silicon wafer is printed with phosphorus diffusion source on one side, and boron diffusion source or boron aluminum diffusion source on the other side; the same diffusion source of the silicon wafer is stacked and loaded into boats; low-pressure diffusion and post-diffusion treatment are performed in a diffusion furnace. After the post-diffusion treatment, the surface of the silicon wafer is textured. 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 coating Afterwards, a negative pressure diffusion process is adopted to reduce the back-to-source situation at the edge of the silicon wafer, the diffusion process steps are simplified, and the diffusion efficiency is improved; the PN junction produced is uniform, which reduces the processing cost of the silicon wafer.

Description

Technical field [0001] The present invention belongs to the fabrication of silicon wafers, and more particularly to a liquid source diffusion process of a silicon glass blunt. Background technique [0002] With the development of semiconductor technology, the requirements for semiconductor surface passivation are getting higher and higher. As a passivation material, good electrical properties, reliability, good chemical stability, operability, and economy. According to the above requirements, the semiconductor passivation special glass begins using a more desirable semiconductor passivation material in the semiconductor industry. The chip made of semiconductor passivation special glass is called glass passivation process chip, which is a GPP chip. [0003] At present, the production of silicon wafers in the industry will use the diffusion process to form a PN knot. At present, the commonly used diffusion process in the industry is generally used by phosphorus source, and the boro...

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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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