Group iii nitride semiconductor device and light-emitting device using the same

Abstract

A Group III nitride semiconductor device and method for producing the same. The device includes a substrate, and a plurality of Group III nitride semiconductor layers provided on the substrate. A first layer which is in contact with the substrate is composed of AlxGa1-x N (0≦x≦1), and the difference in height between a protrusion and a depression which are present at the interface between the first layer and a second layer provided thereon is 10 nm or more and is equal to, or less than, 99% the thickness of the first layer. The method includes a first step of depositing on a substrate, a layer containing fine Group III metal particles containing silicon; a second step of nitridizing the fine particles in an atmosphere containing a nitrogen source; and a third step of growing a Group III nitride semiconductor single crystal on the thus-nitridized fine particles.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This application is a Divisional of U.S. application Ser. No. 10 / 583,336 filed on Jun. 19, 2006, which further claims priority from U.S. Provisional Application No. 60 / 532,924 filed on Dec. 30, 2003, the entire disclosures of which are incorporated herein by reference.TECHNICAL FIELD[0002]The present invention relates to a Group III nitride semiconductor device, exhibiting good crystallinity, which is employed in, for example, light-emitting diodes, laser diodes, and electronic devices.BACKGROUND ART[0003]Group III nitride semiconductors have a direct transition band structure and exhibit bandgap energies corresponding to the energy of visible to ultraviolet light. By virtue of these characteristics, Group III nitride semiconductors are employed at present for producing light-emitting devices, including blue LEDs, blue-green LEDs, ultraviolet LEDs, and white LEDs (which contain a fluorescent substance in combination with such a nitride sem...

AI Technical Summary

Benefits of technology

[0009]An object of the present invention is to provide a Group III nitride semiconductor device exhibiting improved crystallinity and good performance. Another object of the present invention is to provide a Group III nitride semiconductor light-emitting device exhibiting high reverse withstand voltage; i.e., a high threshold voltage at which a reverse current begins to flow.

[0011]According to the present invention, there are obtained a Group III nitride semiconductor device of improved crystallinity, and a Group III nitride semiconductor light-emitting device exhibiting high reverse withstand voltage; i.e., a high threshold voltage at which reverse current begins to flow.

Problems solved by technology

Growing only a nitride single crystal itself has been considered difficult, for the following reasons.

Nitrogen, which is a constituent of the single crystal, has high dissociation pressure and therefore fails to be retained in the single crystal in, for example, the pulling method.

However, even when a nitride semiconductor single crystal is grown directly on such a single-crystal substrate, large amounts of crystal defects, which are attributed to crystal lattice mismatch between the crystalline substrate and the single crystal, are generated in the resultant nitride semiconductor single crystal film; i.e., the epitaxial film fails to exhibit good crystallinity.

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