Phosphoric acid solution exchanging method in semiconductor integrated circuit production

Abstract

The invention discloses a method for exchanging phosphoric acid solution in manufacturing of integrated circuit of a semiconductor and a control program thereof. After a plurality of batches of operation product, corresponding liquid level sensors of an inner groove (21) and an outer groove (22) carry out partial quantity exchanges of the phosphoric acid solution at the control program so as to ensure that the phosphoric acid solution in the groove always keeps a certain solvent capacity to silicon ions; at the same time, an etching rate of the phosphoric acid solution in each operation product number and all service life of the solution to a silica film can reach the requirement of technology, effectively improve and the problem of precipitation of silica kernel, and improve the quality and the qualification rate of the product.

Description

technical field [0001] The invention relates to a phosphoric acid solution exchange method and a control program in the manufacture of semiconductor integrated circuits. Background technique [0002] Shallow junction isolation technology such as silicon oxide isolation technology is generally used for device isolation with a line width of less than 0.25 microns in the integrated circuit manufacturing process. Among them, on the premise of completely etching the silicon nitride film in the diffusion layer region, the requirement for the amount of protrusion of the high-density plasma silicon oxide film in the trench relative to the silicon substrate must be ensured. If the etching amount of the silicon oxide film in the trench is too large to sink below the silicon substrate, it will cause gate short circuit and failure in the subsequent process. [0003] Based on the above considerations, when performing the traditional silicon nitride film etching process, the etching rate...

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Problems solved by technology

The problem brought about by the above-mentioned full-quantity chemical solution exchange method is that as the corrosion continues, the corrosion rate of the silicon oxide film slows down, and when the concentration of silicon ions in the phosphoric acid chemical solution tank reaches saturation, a large amount of carbon dioxide will be precipitated immediately. Small silicon particles adhere to the surface of the silicon wafer, reducing the quality and yield of device products

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