Provided is a nitride semiconductor device with high reliability and high
flexibility in design and manufacture of the device. The nitride semiconductor
device comprises a seed crystal portion (11) formed on a sapphire substrate
(10) and having a mask (12) on one side surface thereof, and a GaN
layer (15) grown on the sapphire substrate (10) and the seed crystal
portion (11) through epitaxial lateral overgrowth. The GaN layer (15)
is grown only from an exposed side surface of the seed crystal portion (11)
which is not covered with the mask (12), so the lateral growth of the GaN
layer (15) is asymmetrically carried out. Thereby, a meeting portion (32)
is formed in the vicinity of a boundary between the seed crystal portion (11)
and the mask (12) in a thickness direction of the GaN layer (15).
Therefore, as the meeting portion (32) is formed in a position away from
the center between the adjacent seed crystal portions (11) in a direction
parallel to a surface of the substrate, a width WL of a lateral growth
region is larger with respect to a pitch WP of the seed crystal potion
(11), compared with conventional configurations.
