Manufacturing method of nitride semiconductor device and nitride semiconductor device

A manufacturing method of a nitride semiconductor device having a nitride semiconductor substrate in which dislocation concentrated regions align in stripe formation, the dislocation concentrated regions extending from a front surface to a back surface of the substrate, the manufacturing method comprising:

• a stacking step of forming nitride semiconductor layers on the front surface of low dislocation regions of the substrate;
• and
• a groove-forming step of, prior to the stacking step, performing groove-forming to at least the low dislocation regions of immediate areas of the dislocation concentrated regions on the front surface, wherein
• an edge is formed at a boundary between a groove and a surface of the low dislocation region, and
• a crystal growth layer is formed to have a part having a slightly upward slope which positionally corresponds to the edge.

A manufacturing method of a nitride semiconductor device having a nitride semiconductor substrate in which dislocation concentrated regions align in stripe formation, the dislocation concentrated regions extending from a front surface to a back surface of the substrate, the manufacturing method comprising:

• a stacking step of forming nitride semiconductor layers on the front surface of low dislocation regions of the substrate;
• and
• a groove-forming step of, prior to the stacking step, performing groove-forming to at least the low dislocation regions of immediate areas of the dislocation concentrated regions on the front surface, wherein
• a groove is in a shape of stairs in a cross section.