One-time Total Diffusion Technology of Phosphorus and Boron Liquid Source

Abstract

The invention discloses a phosphorus and boron liquid source one-shot perfect diffusion process. The process is mainly implemented through the following steps that one surface of each silicon wafer with two thinned sides is rotated to be coated with a liquid boron source, baked and then rotated again to be coated with a liquid phosphorus source, lamination is conducted after baking, the silicon wafers are stacked on a silicon boat pairwise to be subjected to one-shot perfect diffusion in the mode that each phosphorus source surface is opposite to the corresponding phosphorus source surface and each boron source surface is opposite to the corresponding boron source surface. Diffused junction depth is even, and reverse breakdown voltage of a product can be stable and good in uniformity; the diffusion concentration gradient is reduced, PN junction field intensity can be effectively improved, discharging-resistant capacity of the product is improved, and the reverse surge capacity of the product can be effectively improved; meanwhile, the source return quantity of the edge of the silicon wafer is small, the number of intra defects is small, and product reliability is high. Processing cost is low, the process is simple, and production is easy.

Description

technical field [0001] The invention relates to a manufacturing process of a semiconductor device, in particular to a primary total diffusion process of phosphorus and boron liquid sources. Background technique [0002] The manufacture of some devices in the semiconductor industry mostly uses the diffusion process to form a PN junction. At present, the commonly used diffusion process in the industry generally uses one-time full diffusion of phosphorus paper source and boron paper source or two-time diffusion of phosphorus and boron. These diffusion methods have problems. Defects to avoid: 1) The diffusion junction of paper source diffusion is not flat, there are many back sources on the edge of the silicon wafer, and the device’s anti-surge capability is poor; Sandblasting or chemical thinning to remove the anti-source amount, followed by boron diffusion, is costly and prone to debris. Contents of the invention [0003] The technical problem to be solved by the present in...

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Problems solved by technology

[0002] The manufacture of some devices in the semiconductor industry mostly uses the diffusion process to form a PN junction. At present, the commonly used diffusion process in the industry generally uses one-time full diffusion of phosphorus paper source and boron paper source or two-time diffusion of phosphorus and boron. These diffusion methods have problems. Defects to avoid: 1) The diffusion junction of paper source diffusion is not flat, there are many back sources on the edge of the silicon wafer, and the device’s anti-surge capability is poor; Sandblasting or chemical thinning to remove the anti-source amount, and then boron diffusion, the cost is high, and it is easy to cause debris

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