Nichia Corporation

Yoshihito Kawauchi

Yoshiki Inoue

Naoya Sako

Yasunori Nagahama

Yuki Shibutani

Takashi Ohara

Kazuyuki Takeichi

A sapphire substrate provided with a plurality of projections on a principal surface on which a nitride semiconductor is grown to form a nitride semiconductor light emitting element. The projections have a substantially triangular pyramidal-shape the projections having a plurality of side surfaces and a pointed top. The side surfaces have an inclination angle of between 53&#xb0; and 59&#xb0; from a bottom of the projections. The side surfaces are crystal-growth-suppressed surfaces on which a growth of the nitride semiconductor is suppressed relative to a portion of the principal surface located between adjacent projections. A bottom of the projections has a substantially triangular shape having three outwardly curved arc-shaped sides, and each of the side surfaces has a substantially triangular shape having vertexes located at the top of the projection and at both ends of a respective side of the bottom of the projection.

Sapphire substrate and method for manufacturing the same and nitride semiconductor light emitting element

A method for manufacturing a sapphire substrate in which a plurality of projections are formed on a C-plane of the sapphire substrate by etching, includes: forming a patterned etching mask on the C-plane of the sapphire substrate; etching the sapphire substrate until the projections are formed, wherein each of the projections formed by the etching has a substantially triangular pyramidal-shape and has a plurality of side surfaces, a pointed top and a bottom, wherein the bottom of each of the projections has a substantially triangular shape having three outwardly curved arc-shaped sides. The projections are arranged on vertexes of a triangular lattice, and an orientation of the bottom of the projections conforms with an orientation that is rotated by about 30 degrees from an orientation of a triangle of the triangular lattice; and removing the etching mask from the sapphire substrate.

A sapphire substrate provided with a plurality of projections on a principal surface on which a nitride semiconductor is grown to form a nitride semiconductor light emitting element. The projections have a substantially triangular pyramidal-shape the projections having a plurality of side surfaces and a pointed top. The side surfaces have an inclination angle of between 53&#xb0; and 59&#xb0; from a bottom of the projections. The side surfaces are crystal-growth suppressed surfaces on which a growth of the nitride semiconductor is suppressed relative to a portion of the principal surface located between adjacent projections. A bottom of the projections has a substantially triangular shape having three outwardly curved arc-shaped sides, and each of the side surfaces has a substantially triangular shape having vertexes located at the top of the projection and at both ends of a respective side of the bottom of the projection.

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Komatsushima, Japan

Yoshihito Kawauchi