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 0.005
ohm.cm.