Silicon wafer rapid heat treatment phosphorus diffusion gettering technology for manufacture of solar cell

A rapid heat treatment, solar cell technology, applied in sustainable manufacturing/processing, final product manufacturing, circuits, etc., can solve the problem of low photoelectric conversion efficiency of silicon wafers, and achieve the goal of promoting the dissolution and diffusion of impurities, promoting gettering, and improving productivity. Effect

CN101834224AInactive Publication Date: 2010-09-15ZHEJIANG UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2010-09-15
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a silicon wafer phosphorus diffusion gettering technology for manufacture of a solar cell, which comprises the following steps of: coating a phosphorus source on the surface of a silicon wafer; heating the silicon wafer to 800-1,100 DEG C at the rate of 50-200 DEG C / s in the presence of a protective gas atmosphere; preserving the temperature for 1-10 minutes; then cooling to 500-800 DEG C and preserving the temperature for 1-10 minutes; and cooling and then removing a phosphorosilicate glass layer. The invention has short process time, low cost and good gettering effect.
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Description

technical field

[0001] The invention relates to the technical field of silicon solar cell manufacturing, in particular to a phosphorus diffusion gettering process for rapid heat treatment of silicon wafers used in solar cell manufacturing. Background technique

[0002] Since entering the 21st century, with the gradual depletion of primary energy and the increasing demand for energy, human beings are facing more and more serious energy crises. The development and utilization of renewable energy has become the hope to solve the human energy crisis. Among all renewable energy sources, solar energy is a widely distributed and inexhaustible clean energy source with great application prospects. Solar cells are semiconductor devices that convert solar energy into electricity without producing any pollution. Therefore, the development and utilization of solar cells has become a research hotspot worldwide.

[0003] At present, crystalline silicon is the most important solar cell m...

Examples

Embodiment 1

[0027] (1) Take a single crystal silicon wafer contaminated by Cu impurities, such as figure 2 As shown in (a), the body contains point-like copper precipitation, and the minority carrier lifetime is about 3 μs after testing;

[0028] (2) Coat the phosphorus source (p-854, Honeywell) on both sides of the monocrystalline silicon wafer, and then pre-bake it at 200°C for 10 minutes to remove excess organic matter;

[0029] (3) Pass the protective gas (argon gas) into the RTP-300 rapid heat treatment furnace, the air pressure is about 1 atmosphere, and the above-mentioned single crystal silicon wafer is sent into the furnace, and the furnace temperature is raised to 850°C at 50°C / s, and kept for 3 Minutes, then lower the temperature to 650°C at a rate of 50°C / s, and keep it warm for 3 minutes. In addition, take the same treated monocrystalline silicon wafer and keep it at 900°C for 3 minutes. Impurities diffuse from the material body to the surface gettering region;

[0030] (4...

Embodiment 2

[0033] (1) Take a single crystal silicon wafer contaminated by Cu impurities, such as image 3 As shown in (a), the body contains star-shaped copper deposits, and the minority carrier lifetime is about 3 μs after detection;

[0034] (2) Coat the phosphorus source (p-854, Honeywell) on both sides of the monocrystalline silicon wafer, and then pre-bake it at 200°C for 10 minutes to remove the organic matter in the phosphorus source

[0035] (3) Pass the protective gas (argon gas) into the RTP-300 rapid heat treatment furnace, and the air pressure is about 1 atmosphere, and the above-mentioned single crystal silicon wafer is sent into the furnace. Minutes, then lower the temperature to 800°C at a rate of 30°C / s, and keep it warm for 3 minutes. In addition, take the same treated monocrystalline silicon wafer and keep it at 1000°C for 3 minutes, as a control group. Diffusion from the material body to the surface gettering region;

[0036] (4) Cool and remove the phosphosilicate g...

Embodiment 3

[0039] (1) Take a single crystal silicon wafer contaminated by Cu impurities, such as Figure 4 As shown in (a), the body contains star-shaped copper deposits, and the minority carrier lifetime is about 3 μs after detection;

[0040] (2) Coat the phosphorus source (p-854, Honeywell) on both sides of the monocrystalline silicon wafer, and then pre-bake it at 200°C for 10 minutes to remove excess organic matter;

[0041](3) Pass the protective gas (oxygen) into the RTP-300 rapid heat treatment furnace, the air pressure is about 1 atmosphere, and the above-mentioned single crystal silicon wafer is sent into the furnace, and the furnace temperature is raised to 950°C at 200°C / s, and kept for 3 minutes , and then lower the temperature to 700°C at a rate of 10°C / s, and hold for 3 minutes. The holding time selected in the experiment is enough for Cu impurities to diffuse from the material body to the surface gettering area;

[0042] (4) Cool and remove the phosphosilicate glass laye...