Nitride semiconductor light-emitting element and method for producing same

A nitride semiconductor light-emitting element comprising:

• an n-type nitride semiconductor layer;
• a nitride semiconductor active layer provided on said n-type nitride semiconductor layer;
• a p-type nitride semiconductor layer provided on said nitride semiconductor active layer, said p-type nitride semiconductor layer including a first p-type nitride semiconductor layer, a second p-type nitride semiconductor layer and a third p-type nitride semiconductor layer in this order from the side of said nitride semiconductor active layer, said first p-type nitride semiconductor layer and said second p-type nitride semiconductor layer containing Al respectively, said third p-type nitride semiconductor layer having a smaller band gap than said second p-type nitride semiconductor layer;
• and
• an undoped AlxGa(1-x)N layer between said nitride semiconductor active layer and said first p-type nitride semiconductor layer.

A method for producing a nitride semiconductor light-emitting element, comprising the steps of:

• vapor-phase-growing a nitride semiconductor active layer on an n-type nitride semiconductor layer;
• vapor-phase-growing an undoped AlxGa(1-x)N layer on said nitride semiconductor active layer;
• vapor-phase-growing a first p-type nitride semiconductor layer containing Al on said undoped AlxGa(1-x)N layer;
• vapor-phase-growing a second p-type nitride semiconductor layer, containing Al, having an equivalent average Al composition to said first p-type nitride semiconductor layer on said first p-type nitride semiconductor layer;
• vapor-phase-growing a third p-type nitride semiconductor layer having a smaller average Al composition than said first p-type nitride semiconductor layer on said second p-type nitride semiconductor layer;
• and
• vapor-phase-growing a fourth p-type nitride semiconductor layer on said third p-type nitride semiconductor layer after vapor-phase-growing said third p-type nitride semiconductor layer, the p-type impurity concentration in said fourth p-type nitride semiconductor layer being higher than the p-type impurity concentration in said third p-type nitride semiconductor layer.