A Primary Diffusion Process for Adjusting the Diffusion Atmosphere

Abstract

The invention provides a primary diffusion process for adjusting the diffusion atmosphere, which includes setting the coated silicon chip in a diffusion furnace to diffuse according to the diffusion curve, and feeding a certain proportion of nitrogen and oxygen during the diffusion process. The beneficial effects of the present invention are due to the adoption of the above-mentioned technical scheme, by adjusting the ratio of nitrogen and oxygen in the diffusion process of the silicon wafer, especially in the heating process, to control the junction depth, TRR, surface square resistance of the silicon wafer and the subsequent process of silicon wafer diffusion. The test results of the forward voltage of the silicon wafer make the silicon wafer more suitable for different use requirements, so that the junction depth of the silicon wafer, TRR, the surface resistance of the silicon wafer and the value of the forward voltage of the back channel can be effectively controlled, and the required silicon wafer has been obtained. , making silicon wafer diffusion highly operable, simple and convenient.

Description

technical field [0001] The invention belongs to the technical field of silicon chip production, in particular to a primary diffusion process for adjusting the diffusion atmosphere. 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). The production process of silicon wafers for the production of GPP chips includes diffusion process, glass passivation process and gold plating test process, etc. In the diffusion process, the diffusion source is l...

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Problems solved by technology

[0003] In the existing diffusion process, the diffusion source is a gas diffusion source, and the large nitrogen and small nitrogen gases carrying the gas diffusion source are mostly diffused once or multiple times, and the method of high-temperature propulsion after one-step diffusion is mainly used for diffusion. , whether it is the heating process or the cooling process, the introduction of nitrogen and oxygen is carried out; the diffusion of phosphorus source is carried out by using large nitrogen or small nitrogen. In the diffusion process, not only nitrogen and oxygen are introduced, but also phosphorus oxychloride is introduced. gas, and the introduction of nitrogen and oxygen is only used to discharge the air in the diffusion furnace. At the same time, the phosphorus is diffused through one or more diffusions. The diffusion process is complicated, the diffusion time is long, and the work efficiency is low, which cannot meet the existing production needs. At the same time, the depth of the PN junction is not enough, the uniformity of the sheet resistance is poor, the utilization rate of the diffusion gas is not high, and the formed PN junction and the silicon wafer of the sheet resistance cannot meet the required performance requirements

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