The invention discloses a method for reducing bottom
oxygen content of
polycrystalline silicon ingot casting. The method comprises the following steps: 1, preparation of a
crucible bottom
coating, wherein a preparation process comprises: 101, preparing a
coating spraying solution: uniformly mixing an organic grouting agent, de-ionized water and
boron nitride at the
mass ratio of 1 to (2 to 2.5) to (0.8 to 1.2) to obtain the
coating spraying solution; 102, spraying: uniformly spraying the coating spraying solution on an inner bottom surface of a
crucible by adopting spraying equipment and
drying to obtain the bottom coating; 103,
drying:
drying the coating spraying solution sprayed on the inner bottom surface of the
crucible by adopting drying equipment to obtain the bottom coating; 2,
polycrystalline silicon ingot casting: carrying out the
polycrystalline silicon ingot casting by utilizing the crucible with the bottom coating. The method disclosed by the invention is simple in steps, reasonable in design, simple and convenient to realize and good in use effect; one layer of the bottom coating taking the
boron nitride as a main
raw material covers the bottom of the crucible, so that the bottom
oxygen content of the crucible can be effectively reduced, hard inclusion of an
ingot casting finished product can be effectively reduced and the quality of the
ingot casting finished product is improved.