Preparation method for silicon nitride film, solar cell with silicon nitride film and preparation method for solar cell

Abstract

The invention discloses a preparation method for a silicon nitride film, a solar cell with the silicon nitride film and a preparation method for the solar cell. The preparation method for the silicon nitride film includes following steps: S1, placing a silicon wafer into a tubular furnace; S2, feeding nitrogen into the tubular furnace, heating the tubular furnace under the atmosphere of nitrogen to 340 DEG C to 360 DEG C, and maintaining the temperature for 500 seconds to 2000 seconds; and S3, utilizing the PECVD (plasma enhanced chemical vapor deposition) method to sequentially form a first silicon nitride film layer and a second silicon nitride film layer on the silicon wafer. The first silicon nitride film layer is arranged on the silicon wafer before the temperature of the tubular furnace is maintained, so that temperatures around and in the middle of the silicon wafer are uniform after the step of temperature maintaining of the silicon wafer, growth rate of the silicon nitride film around and in the middle of the silicon wafer is guaranteed, overhigh growth rate caused by higher temperature at the edge of the silicon wafer is improved, the problem of color deviation caused by different thicknesses and refractive indexes of the silicon nitride film at various positions on the surface of the silicon wafer is solved, grade of the silicon wafer is lowered, and acceptance rate of the silicon wafer is improved.

Description

technical field

[0001] The invention relates to the field of solar cells, in particular to a method for preparing a silicon nitride film, a solar cell with a silicon nitride film and a method for preparing the same. Background technique

[0002] A solar cell, also called a photovoltaic cell, is a semiconductor device that converts the sun's light directly into electrical energy. Because it is a green product, does not cause environmental pollution, and is a renewable resource, solar cells are an energy source with broad development prospects in today's energy shortage situation. The manufacturing process of solar cells generally has the following steps: chemical cleaning and surface texture treatment, diffusion junction, peripheral etching, silicon nitride film deposition, screen printing, and sintering. In the silicon nitride film deposition step, plasma-enhanced chemical vapor deposition (PECVD) is a commonly used method for preparing silicon nitride films.

[0003] Plas...

Examples

Embodiment approach

[0019] According to a typical embodiment of the present invention, the preparation method of the silicon nitride film comprises the following steps: S1, placing the silicon wafer in the tube furnace; S2, feeding nitrogen into the tube furnace, and setting the tube furnace in The temperature is raised to 340° C. to 360° C. under a nitrogen atmosphere, and the temperature is kept constant for 500s to 2000s; and S3 , forming a first silicon nitride film layer and a second silicon nitride film layer sequentially on the silicon wafer by PECVD method.

[0020] In the present invention, the step of constant temperature of the tube furnace is added before setting the first silicon nitride film layer on the silicon wafer. By constant temperature for a period of time, the temperature of the surrounding and the middle of the silicon wafer is consistent, thus ensuring the temperature of the surrounding and the middle of the silicon wafer. The growth rate of the silicon nitride film is cons...

Embodiment 1

[0033] Introduce nitrogen protection into the quartz tube furnace, push the graphite boat equipped with silicon wafers to be deposited into the quartz tube furnace, raise the temperature to 340°C, feed ammonia gas into the quartz tube furnace with a flow rate of 2800 sccm, and pressurize Under the condition of 1300 mTorr and RF power of 4800W, the PECVD method is used for pretreatment, and the pretreatment time is 200s. After the pretreatment step is completed, the mixed gas is introduced into the quartz tube furnace according to the volume flow ratio of silane and ammonia at 1:3, and the first nitride nitride is deposited by PECVD under the conditions of 1400 mTorr pressure and 5800 W radio frequency power. For the silicon film layer, the deposition time is 120s. According to the volume flow ratio of silane and ammonia gas is 1:9, the mixed gas is introduced into the tube furnace, and the second silicon nitride film layer is deposited by PECVD under the condition of pressure ...

Embodiment 2-3

[0035] The operation steps of Examples 2-3 are the same as those of Example 1, and the specific test conditions such as gas flow rate, pressure, radio frequency power and deposition time are different, see Table 1 for details.

technical field

[0001] The invention relates to the field of solar cells, in particular to a method for preparing a silicon nitride film, a solar cell with a silicon nitride film and a method for preparing the same. Background technique

[0002] A solar cell, also called a photovoltaic cell, is a semiconductor device that converts the sun's light directly into electrical energy. Because it is a green product, does not cause environmental pollution, and is a renewable resource, solar cells are an energy source with broad development prospects in today's energy shortage situation. The manufacturing process of solar cells generally has the following steps: chemical cleaning and surface texture treatment, diffusion junction, peripheral etching, silicon nitride film deposition, screen printing, and sintering. In the silicon nitride film deposition step, plasma-enhanced chemical vapor deposition (PECVD) is a commonly used method for preparing silicon nitride films.

[0003] Plas...

Examples

Embodiment approach

[0019] According to a typical embodiment of the present invention, the preparation method of the silicon nitride film comprises the following steps: S1, placing the silicon wafer in the tube furnace; S2, feeding nitrogen into the tube furnace, and setting the tube furnace in The temperature is raised to 340° C. to 360° C. under a nitrogen atmosphere, and the temperature is kept constant for 500s to 2000s; and S3 , forming a first silicon nitride film layer and a second silicon nitride film layer sequentially on the silicon wafer by PECVD method.

[0020] In the present invention, the step of constant temperature of the tube furnace is added before setting the first silicon nitride film layer on the silicon wafer. By constant temperature for a period of time, the temperature of the surrounding and the middle of the silicon wafer is consistent, thus ensuring the temperature of the surrounding and the middle of the silicon wafer. The growth rate of the silicon nitride film is cons...

Embodiment 1

[0033] Introduce nitrogen protection into the quartz tube furnace, push the graphite boat equipped with silicon wafers to be deposited into the quartz tube furnace, raise the temperature to 340°C, feed ammonia gas into the quartz tube furnace with a flow rate of 2800 sccm, and pressurize Under the condition of 1300 mTorr and RF power of 4800W, the PECVD method is used for pretreatment, and the pretreatment time is 200s. After the pretreatment step is completed, the mixed gas is introduced into the quartz tube furnace according to the volume flow ratio of silane and ammonia at 1:3, and the first nitride nitride is deposited by PECVD under the conditions of 1400 mTorr pressure and 5800 W radio frequency power. For the silicon film layer, the deposition time is 120s. According to the volume flow ratio of silane and ammonia gas is 1:9, the mixed gas is introduced into the tube furnace, and the second silicon nitride film layer is deposited by PECVD under the condition of pressure ...

Embodiment 2-3

[0035] The operation steps of Examples 2-3 are the same as those of Example 1, and the specific test conditions such as gas flow rate, pressure, radio frequency power and deposition time are different, see Table 1 for details.

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