A kind of deposition method of silicon nitride thin film

Abstract

The invention discloses a deposition method of a silicon nitride thin film. According to the method, a plasma enhanced chemical vapor deposition device is adopted to deposit the silicon nitride thin film. In a deposition process, a silicon wafer sequentially passes through a feed chamber, a pre-heating chamber, a process chamber, a cooling chamber and a discharging chamber; the temperature of the feed chamber, pre-heating chamber and process chamber rises with time; the lowest temperature of the feed chamber, the highest temperature of the feed chamber, the lowest temperature of the pre-heating chamber, the highest temperature of the pre-heating chamber, the lowest temperature of the process chamber and the highest temperature of the process chamber are recoded as T1, T1', T2, T2', T3 and T3' respectively, wherein T1' ranges from 200 DEG C to 250 DEG C, and T2 is equal to T1'; and the temperature of the pre-heating chamber when the silicon wafer leaves the pre-heating chamber is the same as the temperature of the process chamber when the silicon wafer enters the process chamber, after the silicon wafer enters the process chamber, the temperature of the process chamber rises to T3'. With the deposition method of the invention adopted, power output and the cracking probability of the silicon wafer are decreased, a hydrogen passivation effect is enhanced, and the efficiency (EFF) of an obtained solar cell is improved by 0.08% compared with that of a product in prior art, and open-circuit voltage (Uoc) and short-circuit current (Isc) are also improved.

Description

technical field [0001] The invention belongs to the field of solar cell manufacturing, and relates to a deposition method of a silicon nitride film, in particular to a deposition method of a silicon nitride film capable of improving the hydrogen passivation effect. Background technique [0002] Conventional fossil fuels are being exhausted day by day. Among the existing sustainable energy sources, solar energy is undoubtedly the cleanest, most common and most potential alternative energy source. Solar power generation devices, also known as solar cells or photovoltaic cells, can directly convert solar energy into electrical energy. The principle of power generation is based on the photovoltaic effect of semiconductor PN junctions. The core of the solar power generation device is the cell, most of which are currently made of silicon wafers. [0003] In the production process of photovoltaic cells, it is necessary to coat a layer of anti-reflection film on the surface of the ...

AI Technical Summary

Problems solved by technology

In the existing PECVD machine, the temperature change curve of the silicon wafer in the process flow with time can be found in figure 1 , the specific process flow is: the silicon wafer is fixed on the graphite frame, and then passes through the preheating chamber, the process chamber, the cooling chamber and the discharge chamber in sequence. Usually, the main function of the preheating chamber is to preheat the silicon wafer, so that Before the silicon nitride is deposited on the silicon wafer, the silicon wafer has a certain temperature. However, the hydrogen passivation effect achieved by the silicon nitride thin film deposition method in the prior art is not ideal, which further leads to a low conversion efficiency of the cell. It needs to be further improved to meet the needs of practical applications

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