Saturated deposition process of graphite boat

Abstract

The invention relates to a saturated deposition process of a graphite boat. The saturated deposition process specifically comprises the following steps: putting a cleaned graphite boat into a furnace tube for preparation of saturated deposition; carrying out pre-bombardment treatment on the graphite boat; depositing a first silicon nitride film on the graphite boat; depositing a silicon carbide film on the graphite boat; and depositing a second silicon nitride film on the graphite boat. A layer of silicon nitride is preferably plated, then a silicon carbide film is plated, and finally a layer of silicon nitride film is plated, and the silicon carbide plated film is located between the two layers of silicon nitride films, so that the silicon carbide film is corroded, and the bottommost layer of silicon nitride film is corroded at the same time; and the silicon carbide film also achieves a state that a great part is corroded and removed, and the residual fine part of silicon carbide is also in a loose and peeled state. According to the graphite boat saturated deposition process, the graphite boat can be cleaned more easily, the cleaning efficiency is improved, and the production efficiency and the production quality are further improved.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to a saturated deposition process of a graphite boat. Background technique [0002] At present, PERC batteries account for a large proportion in the photovoltaic industry. The coating process of PERC batteries mainly uses graphite boats to carry silicon wafers for coating. While coating silicon wafers, graphite is also coated with a film layer. As the number of uses increases, graphite The film layer on the boat is getting thicker and thicker. Generally, the silicon nitride film of graphite boat is used for the positive film, which can be basically removed by soaking in low-concentration hydrofluoric acid; but the back film is composed of aluminum oxide film, silicon nitride film and silicon carbide, which is difficult to remove and easy to remove. The position of graphite boat silicon wafer forms a thick hard shell which is difficult to remove. The hard shell on the graphite ...

AI Technical Summary

Problems solved by technology

Generally, the silicon nitride film of graphite boat is used for the positive film, which can be basically removed by soaking in low-concentration hydrofluoric acid; but the back film is composed of aluminum oxide film, silicon nitride film and silicon carbide, which is difficult to remove and easy to remove. A thick hard shell is formed at the position of graphite boat silicon wafer, which is difficult to remove

The hard shell on the graphite boat can easily scratch and damage the silicon chip during use, resulting in poor EL of the cell

Most companies now use pickling to remove the hard shell, but it is difficult to clean the silicon carbide hard shell on the surface of the graphite boat when cleaning the graphite boat that is saturated with the existing technology, which has caused great difficulties in the industry. Affect production efficiency and reduce production quality

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