Patent ID: 9660140
Date: 2017-05-23
CPC Classifications: H01L

Claim:
1. A method for manufacturing an ultraviolet light-emitting device comprising steps of: preparing a single crystal sapphire substrate having an array of protruding portions on a surface thereof; a buffer layer formation step of an AlN crystal on the surface using an MOVPE method with material gasses of TMAl (tri-methyl-aluminum) gas and ammonia gas; forming an ultraviolet emission layer as a layered stack including, in order from the buffer layer, an n-type conductive layer, a recombination layer, and a p-type conductive layer; forming a first electrode in electrical connection with the n-type conductive layer; and forming a second electrode in electrical connection with the p-type conductive layer; wherein the buffer layer formation step includes; a crystal nucleus formation step that generates crystal nuclei of AlN; an embedding step that fills the spacing among the seed crystal nuclei and forms a base crystal layer of AlN that is carried out subsequent to the crystal nucleus formation step, the embedding step including carrying out an ammonia pulse-flow method growth and a simultaneous supply growth at least one time each, the ammonia pulse-flow method being performed under an enhanced lateral growth condition, with which AlN crystal coherent with the seed crystal nuclei spreads in-plane direction of the single crystal sapphire substrate; and a pillar growth and integration step for forming a pillar array section having an array of pillars that is carried out subsequent to the embedding step that fills the spacing among the seed crystal nuclei, such that each tapered pillar extends from the base crystal layer of AlN on one of the protruding portions and has a base and a tip, each tapered pillar being wider at the tip than at the base, and each tapered pillar being in contact with one of the protruding portions at the base and such that an integration is formed section by merging the pillars together with one another at the tip.