Light-emitting device and method for manufacturing the same

A light-emitting device having a light emitting layer section which comprises a compound semiconductor layer, and an oxide transparent electrode layer for applying drive voltage for light emission to the light emitting layer section, which device being composed so that the light from the light emitting layer section can be extracted through the oxide transparent electrode layer, wherein

• an electrode contact layer, composed of a compound semiconductor, for reducing contact resistance of the oxide transparent electrode layer is arranged between the light emitting layer section and the oxide transparent electrode layer so as to contact with such oxide transparent electrode layer;
• the contacting interface of the oxide transparent electrode layer has a first zone which comprises an area just under bonding pads and a second zone which comprises the residual area, where the second zone is larger in the amount of extracted light than the first zone;
• at least the second zone has formed therein the occupied areas and unoccupied areas for the electrode contact layer arranged in a mixed manner;
• the light emitting layer section is composed of (AlxGa1-x)yIn1-yP (where 0≦x≦1 and 0≦y≦1) or InxGay,Al1-x-yN (where 0≦x≦1, 0≦y≦1 and x+y≦1);
• the light emitting layer section has a double heterostructure which comprises a first conductivity type cladding layer, an active layer and a second conductivity type cladding layer stacked in this order, which layers being respectively composed of the above-described (AlxGa1-x)yIn1-yP or InxGayAl1-x-yN, and the electrode contact layer is formed between the oxide transparent electrode layer and at least either of the first conductivity type cladding layer and second conductivity type cladding layer;
• an ITO electrode layer is provided as the oxide transparent electrode on either side of the first conductivity type cladding layer and the second conductivity type cladding layer so that the light from the light emitting layer section can be extracted through such ITO electrode layer, and the electrode contact layer composed of In-containing GaAs is formed so as to contact with such ITO electrode layer;
• and
• the electrode contact layer has a distribution of the In concentration along the thickness-wise direction thereof such that continuously decreasing as the distance from the ITO electrode layer increases.

A method for manufacturing light-emitting device having a light emitting layer section which is composed of (AlxGa1-x)yIn1-yP (where 0≦x≦1 and 0y≦1), as having a double heterostructure which comprises a first conductivity type cladding layer, an active layer and a second conductivity type cladding layer stacked in this order;

• and having an ITO electrode layer for applying drive voltage for light emission to such light emitting layer section provided on either side of the first conductivity type cladding layer and the second conductivity type cladding layer, comprising the steps of:
• forming a GaAs layer on the light emitting layer section so that occupied areas and unoccupied areas for the GaAs layer are arranged in a mixed manner;
• forming the ITO transparent conductive layer so as to contact with the GaAs layer;
• and
• annealing the ITO electrode layer so as to allow In contained therein to diffuse into the GaAs layer to thereby convert such GaAs layer into an In-containing electrode contact layer.

A light-emitting device having a light emitting layer section which comprises a compound semiconductor layer, and an oxide transparent electrode layer for applying drive voltage for light emission to the light emitting layer section, which device being composed so that the light from the light emitting layer section can be extracted through the oxide transparent electrode layer, wherein

• an electrode contact layer for reducing contact resistance of the oxide transparent electrode layer is arranged between the light emitting layer section and the oxide transparent electrode layer so as to contact with such oxide transparent electrode layer, where on a contacting interface of such oxide transparent electrode layer, occupied areas and unoccupied areas for the electrode contact layer are arranged in a mixed manner;
• the compound semiconductor composing the electrode contact layer is expressed as InxGa1-xAs (0<x≦1) at the contacting interface with the oxide transparent electrode layer;
• and
• the thickness of the electrode contact layer is adjusted within a range from 0.001 μm to 0.02 μm.