Optoelectronic device

Abstract

An optoelectronic device comprises a semiconductor stack, a first metal layer arranged above the semiconductor stack and having a first major plane and a first boundary with a first gradually reduced thickness, and a second metal layer arranged above the first metal layer and having a second major plane and a second boundary with a second gradually reduced thickness, wherein the second major plane parallels to the first major plane and the second boundary exceeds the first boundary, wherein a first angle formed between the first boundary and the semiconductor stack, and/or a second angle formed between the second boundary and the semiconductor stack, is/are less than 10°.

1 . An optoelectronic device, comprising:
 a semiconductor stack;   a first metal layer arranged above the semiconductor stack and having a first major plane and a first boundary with a first gradually reduced thickness; and   a second metal layer arranged above the first metal layer and having a second major plane and a second boundary with a second gradually reduced thickness, wherein the second major plane parallels to the first major plane and the second boundary exceeds the first boundary, wherein a first angle formed between the first boundary and the semiconductor stack, and/or a second angle formed between the second boundary and the semiconductor stack, is/are less than 10°.   
     
     
         2 . The optoelectronic device of  claim 1 , wherein the semiconductor stack comprises a first semiconductor layer, an active layer, and a second semiconductor layer, wherein the first semiconductor layer, the second semiconductor layer and the active layer comprise III-V semiconductor materials including AlGaInP series, and AlGaInN series, or the group of ZnO series. 
     
     
         3 . The optoelectronic device of  claim 1 , wherein the first metal layer comprises Ag, Rh, Pd, Al, Pt, or alloys thereof. 
     
     
         4 . The optoelectronic device of  claim 1 , wherein the reflectivity of the first metal layer is larger than 90%. 
     
     
         5 . The optoelectronic device of  claim 1 , wherein the second metal layer comprises a metal having higher or lower tensile strain than that of the material of the first metal layer. 
     
     
         6 . The optoelectronic device of  claim 1 , wherein the second metal layer comprises Ti, V, Cr, Ni, Cu, Nb, Ru, Pd, or alloys thereof. 
     
     
         7 . The optoelectronic device of  claim 1 , wherein a minimum distance between the first boundary and the second boundary is more than 3 μm. 
     
     
         8 . The optoelectronic device of  claim 1 , further comprising a third metal layer formed above the second metal layer and having a third boundary with a third gradually reduced thickness, wherein the third boundary exceeds the second boundary. 
     
     
         9 . The optoelectronic device of  claim 8 , wherein the third metal layer functions as a diffusion barrier. 
     
     
         10 . The optoelectronic device of  claim 9 , wherein the reflectivity of the third metal layer is smaller than the reflectivity of the first metal layer.