A light emitting device comprising: a conductive support substrate; a bonding layer on the conductive support substrate; a reflective layer on the bonding layer; and a light emitting structure layer on the reflective layer; characterized in that the bonding layer comprises a solder bonding layer (173, 174) on the conductive support substrate, a diffusion barrier layer on the solder bonding layer (173, 174), and an adhesion layer on the diffusion barrier layer; the reflective layer is embedded in the adhesion layer; an ohmic contact layer is located on the reflective layer; a protective layer is formed on a boundary region of the adhesion layer and surrounds the ohmic contact layer, such that the adhesion layer contacts the reflective layer, the ohmic contact layer, and the protective layer; a current blocking layer is embedded in the ohmic contact layer; the light emitting structure comprises a second conductive semiconductor layer, an active layer and a first conductive semiconductor layer; the second conductive semiconductor layer contacts the top surface of the ohmic contact layer, of the current blocking layer and a portion of the protective layer;and a passivation layer is disposed on a side surface of the light emitting structure layer and on a portion of the protective layer that is not in contact with the second conductive semiconductor layer; wherein the solder bonding layer (173, 174) includes a metal or an alloy including at least one of Sn, In, Ga, Bi, Pb, and Au; wherein the diffusion barrier layer is formed of an alloy including Cu or Nb; wherein the adhesion layer comprises a metal or an alloy including at least one of Cu, Nb, Sn, In, Sc, Ta, V, Si, Ag, Au, Zn, Sb, Al, Ge, Hf, La, Mg, Mn, Ni, Pd, and Ti, and wherein the reflective layer comprises an alloy including Ag. a conductive support substrate; a bonding layer on the conductive support substrate; a reflective layer on the bonding layer; and a light emitting structure layer on the reflective layer; characterized in that the bonding layer comprises a solder bonding layer (173, 174) on the conductive support substrate, a diffusion barrier layer on the solder bonding layer (173, 174), and an adhesion layer on the diffusion barrier layer; the reflective layer is embedded in the adhesion layer; an ohmic contact layer is located on the reflective layer; a protective layer is formed on a boundary region of the adhesion layer and surrounds the ohmic contact layer, such that the adhesion layer contacts the reflective layer, the ohmic contact layer, and the protective layer; a current blocking layer is embedded in the ohmic contact layer; the light emitting structure comprises a second conductive semiconductor layer, an active layer and a first conductive semiconductor layer; the second conductive semiconductor layer contacts the top surface of the ohmic contact layer, of the current blocking layer and a portion of the protective layer;and a passivation layer is disposed on a side surface of the light emitting structure layer and on a portion of the protective layer that is not in contact with the second conductive semiconductor layer; wherein the solder bonding layer (173, 174) includes a metal or an alloy including at least one of Sn, In, Ga, Bi, Pb, and Au; wherein the diffusion barrier layer is formed of an alloy including Cu or Nb; wherein the adhesion layer comprises a metal or an alloy including at least one of Cu, Nb, Sn, In, Sc, Ta, V, Si, Ag, Au, Zn, Sb, Al, Ge, Hf, La, Mg, Mn, Ni, Pd, and Ti, and wherein the reflective layer comprises an alloy including Ag.