Method of manufacturing semiconductor device

A method of manufacturing a semiconductor device, the method comprising:

• forming a first AlN layer on a first main surface of an SiC single-crystal substrate;
• etching the first AlN layer without using a mask to form a plurality of pieces of AlN seed crystals on the first main surface from the first AlN layer only by sublimating the first AlN layer without using a mechanical process;
• forming a second AlN layer on the first main surface using the AlN seed crystals as growth nuclei, after etching the first AlN layer;
• and
• forming a nitride semiconductor layer containing Ga on the second AlN layer,
• wherein the forming a first AlN layer includes supplying a trimethylaluminum gas, an ammonia gas, and a hydrogen gas into a film formation chamber at a temperature of 1000° C. to 1200° C. inclusive, and
• wherein the etching a first AlN layer includes partly sublimating the first AlN layer by stopping supply of the trimethylaluminum gas into the film formation chamber while maintaining supply of the ammonia gas and the hydrogen gas into the film formation chamber at a temperature of 1000° C. to 1200° C. inclusive.