US 5,408,120 A · Light-emitting device of gallium nitride compound semiconductor

Abstract

A light-emitting diode of GaN compound semiconductor emits a blue light from a plane rather than dots for improved luminous intensity. This diode includes a first electrode associated with a high-carrier density n.sup.+ layer and a second electrode associated with a high-impurity density i.sub.H -layer. These electrodes are made up of a first Ni layer (110 .ANG. thick), a second Ni layer (1000 .ANG. thick), an Al layer (1500 .ANG. thick), a Ti layer (1000 .ANG. thick), and a third Ni layer (2500 .ANG. thick). The Ni layers of dual structure permit a buffer layer to be formed between them. This buffer layer prevents the Ni layer from peeling. The direct contact of the Ni layer with GaN lowers a drive voltage for light emission and increases luminous intensity.

Claims14

Dependent claims

A light-emitting device of gallium nitride compound semiconductor material comprising:

an n-layer of n-type gallium nitride compound semiconductor material (Al.sub.x Ga.sub.1-x N, x.gtoreq.0);
and
an i-layer of i-type gallium nitride compound semiconductor material (Al.sub.x Ga.sub.1-x N, x.gtoreq.0) doped with a p-type impurity;
wherein a first electrode layer including Ni is formed in contact with said i-layer and functions as an electrode therefore;
and
wherein said first electrode layer is a multi-layer structure having a first Ni layer of predetermined thickness formed over said i-layer, a second Ni layer which is thicker than said first Ni layer and formed thereon, an Al layer formed over said second Ni layer, a Ti layer formed over said Al layer, and a third Ni layer which is thicker than said first Ni layer formed over said Ti layer.

3 more elements

A light-emitting device of gallium nitride compound semiconductor, comprising:

at least two layers of gallium nitride compound semiconductor material (Al.sub.x Ga.sub.1-x N, x.gtoreq.0);
a first electrode layer for one layer of said at least two layers;
and
a second electrode layer for another of said at least two layers;
said first and second electrode layers provide an improved luminous intensity of said light-emitting device;
wherein at least one layer of said first and second electrode layers includes a contact layer made of one of Ni, Ag, an alloy including Ni, an alloy including Ag, and an alloy including Ti, said contact layer being directly contacted with any of said at least two layers of gallium nitride compound semiconductor material (Al.sub.x Ga.sub.1-x N, x.gtoreq.0).

3 more elements

Dependencies are inferred from the claim text.

Light-emitting device of gallium nitride compound semiconductor

Life of this patent

Light-emitting device of gallium nitride compound semiconductor

Life of this patent

Abstract

Claims14