Preparation process of N-type heavily-doped phosphorus master alloy silicon rod

Abstract

The invention discloses a preparation process of an N-type heavily-doped phosphorus master alloy silicon rod. The preparation process comprises the following steps of: selecting a single crystal furnace, a 20 graphite thermal field and a 20 quartz crucible, and heating to melt 70kg of polycrystalline silicon; placing 520g of N high-purity red phosphorus into a quartz doper; installing an adapting doper at a seed crystal bayonet, ascending the adapting doper into an auxiliary chamber of the single crystal furnace to guide air, then, opening a flap valve, descending the quartz doper to a tested 390-mm position, enabling the air to be sublimated and automatically guided into a silicon melt, and pulling crystals under the conditions that the rotating speed of a crystal rod is 12r / min, the rotating speed of the crucible is 8r / min, the pulling speed of the head of the crystal rod is 1.1mm / min, and the pressure of the furnace is 2000-2500Pa; and cutting the pulled crystal rod into cakes with the thickness of 2cm, grading according to the electrical resistivity, then, treating by using a water quenching technology, pickling, then, preparing fragments with the size of 5-20mm by using a silicon briquette mutual-collision method, packaging according to different grades, and labeling for self use or sell. The safety in preparing the N-type heavily-doped phosphorus master alloy silicon rod is ensured, and the electrical resistivity of the crystal rod is uniform and ranges from 0.001 to 0.005ohm.cm.

Description

technical field [0001] The invention relates to a preparation process of an N-type heavily doped phosphorus master alloy silicon rod. Background technique [0002] High-purity crystalline silicon is an important solar photovoltaic material. Doping a small amount of group IIIA elements (such as boron) into single crystal silicon forms a p-type silicon semiconductor; doping a small amount of group VA elements (such as phosphorus) forms an n-type semiconductor. Both materials can be made into solar cells, which convert solar radiation into electricity. [0003] Silicon, a semiconductor element, belongs to the four main group elements in the periodic table of elements, and the number of electrons in the outermost shell of its atom is 4, which is a relatively stable element. If group III boron is added, because the outermost layer of the boron atom has only three electrons, it has one electron less than the outer layer of the silicon atom. After the boron atom is doped in the ...

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Problems solved by technology

It is an important parameter in the design and production of solar cells, but it will be affected by the high temperature treatment process

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