ZINC OXIDE BASED SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME

• US 20100258795A1
• Filed: 04/08/2010
• Published: 10/14/2010
• Est. Priority Date: 04/10/2009
• Status: Active Grant

• Current Assignee: Stanley Electric Company Limited
• Original Assignee: Stanley Electric Company Limited
• Inventors: HORIO, Naochika
• Granted Patent: US 8,735,195 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 21/02403 Oxides
• CPC Class Codes: H01L 21/02433 Crystal orientation
• CPC Class Codes: H01L 21/02472 Oxides
• CPC Class Codes: H01L 21/02554 Oxides
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/02573 Conductivity type
• CPC Class Codes: H01L 33/0083 for devices with an active region comprising only II-VI compounds
• CPC Class Codes: H01L 33/28 containing only elements of Group II and Group VI of the Periodic Table
• CPC Class Codes: H01L 33/36 characterised by the electrodes
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/42 Transparent materials

Abstract

Disclosed is a method of manufacturing a ZnO-based semiconductor device having at least p-type ZnO-based semiconductor layer, which includes a step of forming a contact metal layer on the p-type ZnO-based semiconductor layer wherein the contact metal layer contains at least one of Ni and Cu; and a step of performing heat treatment of the contact metal layer and the p-type ZnO-based semiconductor layer under an oxygen-free atmosphere to form a mixture layer including elements of the p-type ZnO-based semiconductor layer and the contact metal layer at a boundary region therebetween while maintaining a metal phase layer on a surface of the contact metal layer.

Claims

1. A method of manufacturing a zinc oxide (ZnO) based semiconductor device having at least p-type ZnO-based semiconductor layer, comprising:

a contact metal layer formation step of forming a contact metal layer on the p-type ZnO-based semiconductor layer wherein the contact metal layer contains at least one of nickel (Ni) and copper (Cu); and

a heat treatment step of performing heat treatment of the contact metal layer and the p-type ZnO-based semiconductor layer under an oxygen-free atmosphere to form a mixture layer comprising elements of the p-type ZnO-based semiconductor layer and the contact metal layer at a boundary region between the p-type ZnO-based semiconductor layer and the contact metal layer while maintaining a metal phase layer on a surface of the contact metal layer.

2. The method according to claim 1, wherein the oxygen-free atmosphere is any one of vacuum, an inert gas atmosphere, a reductive gas atmosphere, and a mixture of an inert gas and a reductive gas.

3. The method according to claim 1, wherein the heat treatment is performed at a temperature in the range of 350 to 450°

C.

4. The method according to claim 1, wherein a thickness of the contact metal layer is in the range of 3 nm to 30 nm.

5. The method according to claim 1, further comprising a step of forming a barrier metal layer and a pad metal layer on the contact metal layer after performing the heat treatment step.

6. The method according to claim 5, wherein the barrier metal layer comprises at least one of platinum (Pt), rhodium (Rh), palladium (Pd), iridium (Ir), titanium (Ti) and tungsten (W).

7. The method according to claim 1, wherein the ZnO-based semiconductor device is a light emitting diode (LED) including an n-type ZnO-based semiconductor layer and a light emitting layer.

8. A ZnO-based semiconductor device having at least p-type ZnO-based semiconductor layer, comprising:

a contact electrode layer formed on the p-type ZnO-based semiconductor layer, the contact electrode layer comprising at least one of Ni and Cu; and

a pad electrode formed on the contact electrode layer,

wherein the contact electrode layer includes a metal phase layer formed on a surface of the contact electrode layer and a mixture layer comprising elements of the p-type ZnO-based semiconductor layer and the contact electrode layer, the mixture layer being formed at a boundary region between the p-type ZnO-based semiconductor layer and the contact electrode layer.

9. The semiconductor device according to claim 8, wherein the contact electrode layer is formed by heat treatment under an oxygen-free atmosphere.

10. The semiconductor device according to claim 8, further comprising a barrier metal layer formed between the contact electrode layer and the pad electrode.

11. A method for forming a contact electrode for a p-type ZnO-based semiconductor, comprising:

a step of forming a contact metal layer on the p-type ZnO-based semiconductor, the contact metal layer comprising at least one of Ni and Cu; and

a step of performing heat treatment of the p-type semiconductor having the contact metal layer formed thereon under an oxygen-free atmosphere, to form a mixture region comprising elements of the p-type ZnO-based semiconductor layer and the contact metal layer at a boundary between the p-type ZnO-based semiconductor layer and the contact metal layer while maintaining a metal phase layer on a surface of the contact metal layer.

12. The method according to claim 11, wherein the oxygen-free atmosphere is any one vacuum, an inert gas atmosphere, a reductive gas atmosphere, a mixture of an inert gas and a reductive gas.

13. The method according to claim 11, wherein the heat treatment is performed at a temperature in the range of 350 to 450°

C.