Method of manufacturing group-III nitride semiconductor light emitting device, group III nitride semiconductor light emitting device and lamp

A method of manufacturing a Group-III nitride semiconductor light-emitting device, comprising:

• activating a gas including a Group-V element and a metal material with plasma, thereby reacting the gas with the metal material, to form, on a substrate, an intermediate layer that is made of a Group-III nitride compound;
• and
• stacking an n-type semiconductor layer that is made of a Group-III nitride semiconductor, a light-emitting layer, and a p-type semiconductor layer, sequentially on the intermediate layer, said n-type semiconductor layer comprises an undercoat layer and an n-type contact layer, said stacking comprises forming the undercoat layer in an undoped state without supplying a doping element, stacking the undercoat layer on the intermediate layer and stacking the n-type contact layer on the undercoat layer, the n-type contact layer having the same composition as that of the undercoat layer except that the n-type contact layer is doped with an n-type impurity,
• wherein the Group-V element is nitrogen, the gas fraction of nitrogen in the gas is controlled within a range of more than 75% to less than 99% during forming of the intermediate layer, and the intermediate layer is formed into a single crystal structure.