Patent ID: 8921886

Claim:
A semiconductor light emitting device comprising: a stacked structure body having a first conductivity type first semiconductor layer including a nitride-based semiconductor, a second conductivity type second semiconductor layer including a nitride-based semiconductor, and a light emitting layer provided between the first semiconductor layer and the second semiconductor layer; and an electrode having a first metal layer provided on the second semiconductor layer and including silver or silver alloy, a second metal layer provided on the first metal layer and including at least one element of platinum, palladium, rhodium, iridium, ruthenium, osmium, and a third metal layer provided on the second metal layer, a thickness of the third metal layer along a direction from the first semiconductor layer toward the second semiconductor layer being equal to or greater than a thickness of the second metal layer along the direction, wherein the electrode further includes a fourth metal layer on a side opposite to the second semiconductor layer with respect to the third metal layer, and a diffusion coefficient of the third metal layer to the fourth metal layer is smaller than a diffusion coefficient of the second metal layer to the fourth metal layer.