Semiconductor light-emitting device and method of fabricating the same

Abstract

The invention provides a semiconductor light-emitting device with II-V group (or II-IV-V group) compound contact layer and a method of fabricating the same. The semiconductor light-emitting device according to a preferred embodiment of the invention includes a substrate, a first conductive type semiconductor material layer, a light-emitting layer, a first electrode, a second conductive type semiconductor material layer, a H-V group (or II-W-V group) compound contact layer, a transparent conductive layer, and a second electrode. The existence of the II-V group (or II-IV-V group) compound contact layer improves the ohmic contact between the second conductive type semiconductor material layer and the transparent conductive layer.

1 . A method of making a semiconductor light-emitting device, said method comprising the steps of:
 preparing a substrate;   forming a first conductive type semiconductor material layer on the substrate;   forming a light-emitting layer on the first conductive type semiconductor material layer;   forming a second conductive type semiconductor material layer on the light-emitting layer;   forming a II-V group compound contact layer on the second conductive type semiconductor material layer;   partially removing the TI-V group compound contact layer, the second conductive type semiconductor material layer, the light-emitting layer, and the first conductive type semiconductor material layer such that a partial area of the first conductive type semiconductor material layer is exposed;   forming a first electrode on the exposed partial area of the first conductive type semiconductor material layer;   forming a transparent conductive layer on the II-V group compound contact layer;   partially removing the transparent conductive layer such that a partial area of the II-V group compound contact layer is exposed; and   forming a second electrode on the exposed partial area of the II-V group compound contact layer such that the second electrode contacts the transparent conductive layer.   
   
   
       2 . The method of  claim 1 , wherein the substrate is formed of a material selected from a group consisting of Si, GaN, AlN, sapphire, spinnel, SiC, GaAs, Al 2 O 3 , LiGaO 2 , LiAlO 2 , and MgAl 2 O 4 . 
   
   
       3 . The method of  claim 11 , wherein the first conductive type semiconductor material layer and the second conductive type semiconductor material layer are formed of a GaN material, respectively. 
   
   
       4 . The method of  claim 1 , wherein the first conductive type is N-type, and the second conductive type is P-type. 
   
   
       5 . The method of  claim 1 , wherein the light-emitting layer is formed of a material selected from a group consisting of InGaN, AlGaN, and InGaAs. 
   
   
       6 . The method of  claim 1 , wherein a II group chemical element in the II-V group compound contact layer is one selected from the group consisting of Zn, Be, Mg, Ca, Sr, Ba, and Ra, and a V group chemical element in the TI-V group compound contact layer is one selected from the group consisting of N, P, As, Sb, and Bi. 
   
   
       7 . The method of  claim 1 , wherein the material of the II-V group compound contact layer is represented by the general formula: M x N y , where M represents the II group chemical element, N represents the V group chemical element, 1≦x≦3, and 1≦y≦3; x and y are molar numbers. 
   
   
       8 . The method of  claim 1 , wherein the thickness of the II-V group compound contact layer ranges from 0.5 Angstroms to 500 Angstroms. 
   
   
       9 . The method of  claim 1 , wherein the II-V group compound contact layer is formed at a temperature ranging from 400° C. to 1100° C. 
   
   
       10 . The method of  claim 1 , wherein the transparent conductive layer is formed of a material selected from a group consisting of Ni/Au, ITO, CTO, TiWN, In 2 O 3 , SnO 2 , CdO, ZnO, CuGaO 2 , and SrCu 2 O 2 . 
   
   
       11 . A method of making a semiconductor light-emitting device, said method comprising the steps of:
 preparing a substrate;   forming a first conductive type semiconductor material layer on the substrate;   forming a light-emitting layer on the first conductive type semiconductor material layer;   forming a second conductive type semiconductor material layer on the light-emitting layer;   forming a II-IV-V group compound contact layer on the second conductive type semiconductor material layer;   partially removing the II-IV-V group compound contact layer, the second conductive type semiconductor material layer, the light-emitting layer, and the first conductive type semiconductor material layer such that a partial area of the first conductive type semiconductor material layer is exposed;   forming a first electrode on the exposed partial area of the first conductive type semiconductor material layer;   forming a transparent conductive layer on the II-IV-V group compound contact layer;   partially removing the transparent conductive layer such that a partial area of the II-IV-V group compound contact layer is exposed; and   forming a second electrode on the exposed partial area of the II-IV-V group compound contact layer such that the second electrode contacts the transparent conductive layer.   
   
   
       12 . The method of  claim 11 , wherein the substrate is formed of a material selected from a group consisting of Si, GaN, AlN, sapphire, spinnel, SiC, GaAs, Al 2 O 3 , LiGaO 2 , LiAlO 2 , and MgAl 2 O 4 . 
   
   
       13 . The method of  claim 11 , wherein the first conductive type semiconductor material layer and the second conductive type semiconductor material layer are formed of a GaN material, respectively. 
   
   
       14 . The method of  claim 11 , wherein the first conductive type is N-type, and the second conductive type is P-type. 
   
   
       15 . The method of  claim 11 , wherein the light-emitting layer is formed of a material selected from a group consisting of InGaN, AlGaN, and, InGaAs. 
   
   
       16 . The method of  claim 11 , wherein a II group chemical element in the II-IV-V group compound contact layer is one selected from the group consisting of Zn, Be, Mg, Ca, Sr, Ba, and Ra, and a IV group chemical element in the II-IV-V group compound contact layer is one selected from the group consisting of C, Si, Ge,  Sn , and Pb, and a V group chemical element in the II-IV-V group compound contact layer is one selected from the group consisting of N, P, As, Sb, and Bi. 
   
   
       17 . The method of  claim 11 , wherein the material of the II-IV-V group compound contact layer is represented by the general formula: M x N y Q z , where M represents the II group chemical element, N represents the IV group chemical element, Q represents the V group chemical element, 1≦x≦3, 1≦y≦3 and 1≦z≦3; and x and y and z are molar numbers. 
   
   
       18 . The method of  claim 11 , wherein the thickness of the II-IV-V group compound contact layer ranges from 0.5 Angstroms to 500 Angstroms. 
   
   
       19 . The method of  claim 11 , wherein the II-IV-V group compound contact layer is formed at a temperature ranging from 400° C. to 1100° C. 
   
   
       20 . The method of  claim 11 , wherein the transparent conductive layer is formed of a material selected from a group consisting of Ni/Au, ITO, CTO, TiWN, In 2 O 3 , SnO 2 , CdO, ZnO, CuGaO 2 , and SrCu 2 O 2 .