Light emitting element
View Patent ↗An InGaN active layer is formed on a sapphire substrate. A p-side electrode is formed on the InGaN active layer to supply an electric current to this InGaN active layer. The p-side electrode includes {circle around (1)} an Ni layer for forming an ohmic contact with a p-GaN layer, {circle around (2)} an Mo layer having a barrier function of preventing diffusion of impurities, {circle around (3)} an Al layer as a high-reflection electrode, {circle around (4)} a Ti layer having a barrier function, and {circle around (5)} an Au layer for improving the contact with a submount on a lead frame. The p-side electrode having this five-layered structure realizes an ohmic contact and high reflectance at the same time.
1. A light emitting element comprising:
a substrate;
a light emitting layer formed on said substrate to emit light, wherein said light emitting layer includes a first semiconductor layer, an active layer formed on said first semiconductor layer to emit the light and a second semiconductor layer formed on said active layer;
a first electrode contacting said second semiconductor layer; and
a second electrode contacting said first semiconductor layer, wherein said first electrode comprising:
an ohmic layer in ohmic contact with said second semiconductor layer;
a first barrier layer formed on said ohmic layer;
a light reflecting layer formed on said first barrier layer and comprising a metal including Ag;
a second barrier layer formed on said light reflecting layer; and
an overcoat electrode for mounting formed on said second barrier layer;
wherein said first barrier layer comprises a material different from that of said ohmic layer and said light reflecting layer comprises a material different from that of said overcoat electrode.
2. A light emitting element comprising:
a substrate;
a light emitting layer formed on said substrate to emit light, wherein said light emitting layer includes a first semiconductor layer, an active layer formed on said first semiconductor layer to emit the light and a second semiconductor layer formed on said active layer;
a first electrode contacting said second semiconductor layer; and
a second electrode contacting said first semiconductor layer, wherein said first electrode comprising:
an ohmic layer in ohmic contact with said second semiconductor layer and comprising a metal including Pt;
a first barrier layer formed on said ohmic layer, comprising a metal including Pt;
a light reflecting layer formed on said first barrier layer;
a second barrier layer formed on said light reflecting layer; and
an overcoat electrode for mounting formed on said second barrier layer,
wherein said light reflecting layer comprises a material different from that of said overcoat electrode.
3. A light emitting element comprising:
a substrate;
a light emitting layer formed on said substrate to emit light, wherein said light emitting layer includes a first semiconductor layer, an active layer formed on said first semiconductor layer to emit the light and a second semiconductor layer formed on said active layer;
a first electrode contacting said second semiconductor layer; and
a second electrode contacting said substrate, wherein said first electrode comprising;
an ohmic layer in ohmic contact with said second semiconductor layer;
a first barrier layer formed on said ohmic layer;
a light reflecting layer formed on said first barrier layer and comprising a metal including Ag;
a second barrier layer formed on said light reflecting layer; and
an overcoat electrode for mounting formed on said second barrier layer,
wherein said first barrier layer comprises a material different from that of said ohmic layer and said light reflecting layer comprises a material different from that of said overcoat electrode.
4. A light emitting element comprising:
a substrate;
a light emitting layer formed on said substrate to emit light, wherein said light emitting layer includes a first semiconductor layer, an active layer formed on said first semiconductor layer to emit the light and a second semiconductor layer formed on said active layer;
a first electrode contacting said second semiconductor layer; and
a second electrode contacting said substrate, wherein said first electrode comprising:
an ohmic layer in ohmic contact with said second semiconductor layer and comprising a metal including Pt;
a first barrier layer formed on said ohmic layer, comprising a metal including Pt;
a light reflecting layer formed on said first barrier layer;
a second barrier layer formed on said light reflecting layer; and
an overcoat electrode for mounting formed on said second barrier layer,
wherein said light reflecting layer comprises a material different from that of said overcoat electrode.