Optoelectronic semiconductor component with current spreading layer
View Patent ↗An optoelectronic semiconductor component comprising a semiconductor body ( 10 ) and a current spreading layer ( 3 ) is specified. The current spreading layer ( 3 ) is applied to the semiconductor body ( 10 ) at least in places. In this case, the current spreading layer ( 3 ) contains a metal ( 1 ) that forms a transparent electrically conductive metal oxide ( 2 ) in the current spreading layer, and the concentration (x) of the metal ( 1 ) decreases from that side of the current spreading layer ( 3 ) which faces the semiconductor body ( 10 ) toward that side of said current spreading layer which is remote from the semiconductor body ( 10 ). A method for producing such a semiconductor component is also disclosed.
1. A method for producing an optoelectronic semiconductor component comprising a semiconductor body having a semiconductor layer sequence which generates electro-magnetic radiation or which converts electromagnetic radiation into electrical charges; and a current spreading layer, which is applied to the semiconductor body at least in places; the current spreading layer containing a metal that forms a transparent electrically conductive metal oxide in the current spreading layer, a concentration of the metal decreasing from that side of the current spreading layer which faces the semiconductor body toward that side of said current spreading layer which is remote from the semiconductor body, and the concentration of the metal being a highest value at an interface between the semiconductor body and the current spreading layer; a concentration of oxygen in the transparent electrically conductive metal oxide in the current spreading layer increasing in accordance with the decrease in the concentration of the metal with increasing distance from the semiconductor body; on the side of the current spreading layer which faces the semiconductor body the current spreading layer consisting of the metal that forms the transparent electrically conductive metal oxide and the current spreading layer consists of the metal oxide on its side remote from the semiconductor body, the method comprising:
applying the metal to the semiconductor body and oxidizing the metal at an increasing rate during the application and oxidation of the metal to produce the current spreading layer; and
increasing the oxygen flow continuously during the application and oxidation of the metal.
2. The method as claimed in claim 1 , wherein the concentration of the metal decreases continuously in the current spreading layer.
3. The method as claimed in claim 1 , wherein the current spreading layer comprises in places a metal oxide having a stoichiometric composition.
4. The method as claimed in claim 1 , wherein the current spreading layer comprises oxides of at least one of the following metals: indium, tin, indium-tin, zinc, cadmium, titanium.
5. The method as claimed in claim 1 , wherein the current spreading layer is applied to a radiation passage area of the semiconductor body.
6. The method as claimed in claim 1 , wherein the current spreading layer is formed by reactive sputtering of the metal.
7. The method as claimed in claim 1 , wherein parts of the current spreading layer which consist of the metal are in direct contact with the semiconductor body.