Method for reducing silicon carbide epitaxial base plane dislocation

The invention discloses a method for reducing silicon carbide epitaxial base plane dislocation, and belongs to the technical field of silicon carbide crystal materials. The method comprises the following steps: grinding and mechanically polishing a silicon carbide crystal substrate; covering the surface of the substrate with a layer of carbon film and then carrying out annealing treatment or carrying out annealing treatment on the substrate in an argon atmosphere to release residual processing stress during thickness removal; the heat preservation time of the annealing treatment is 3-4 hours; after annealing, the carbon film is removed from the substrate covered with the carbon film, and then chemical mechanical polishing is carried out; directly carrying out chemical mechanical polishing on the substrate subjected to annealing treatment in an argon atmosphere; performing epitaxy after chemical mechanical polishing; the annealed substrate is subjected to epitaxy, the base plane dislocation conversion rate rea