ZnO-based thin film and ZnO-based semiconductor element
Provided are a ZnO-based thin film and a ZnO-based semiconductor device which allow: reduction in a burden on a manufacturing apparatus; improvement of controllability and reproducibility of doping; and obtaining p-type conduction without changing a crystalline structure. In order to be formed into a p-type ZnO-based thin film, a ZnO-based thin film is formed by employing as a basic structure a superlattice structure of a MgZnO/ZnO super lattice layer 3 . This superlattice component is formed with a laminated structure which includes acceptor-doped MgZnO layers 3 b and acceptor-doped ZnO layers 3 a . Hence, it is possible to improve controllability and reproducibility of the doping, and to prevent a change in a crystalline structure due to a doping material.
1. A ZnO-based thin film which is a p-type superlattice component with a repeatedly laminated structure of a MgZnO layer and a ZnO layer, wherein
the repeatedly laminated structure includes a plurality of repetitions of a combination of a MgZnO layer and a ZnO layer, and
the MgZnO layers are doped with an acceptor and the ZnO layers are not intentionally doped with the acceptor.
2. The ZnO-based thin film according to claim 1 , wherein a Mg composition ratio of the MgZnO layer is not higher than 50%.
3. The ZnO-based thin film according to claim 1 , wherein a Mg composition ratio of the MgZnO layer is not higher than 30%.
4. The ZnO-based thin film according to claim 1 , wherein film thicknesses of the respective layers in the superlattice component are not more than 10 nm.
5. The ZnO-based thin film according to claim 1 , wherein the acceptor is any one of nitrogen and copper.
6. A ZnO-based semiconductor device comprising a laminated body containing ZnO-based semiconductor in which the ZnO-based thin film according to claim 1 is used as a p-type layer.
7. The ZnO-based semiconductor device according to claim 6 , wherein
the laminated body contains a Mg Y Zn 1-Y O (0≦Y<1) substrate and an n-type MgZnO layer disposed on the Mg Y Zn 1-Y O (0≦Y<1) substrate and a MgZnO/ZnO active layer disposed on the n-type MgZnO layer and the superlattice component disposed on the MgZnO/ZnO active layer.
8. The ZnO-based semiconductor device according to claim 6 , wherein
the laminated body contains a Mg Y Zn 1-Y O (0≦Y<1) substrate and an n-type MgZnO layer disposed on the Mg Y Zn 1-Y O (0≦Y<1) substrate and a superlattice component disposed on the n-type MgZnO layer and an n-type ZnO layer disposed on the superlattice component.