Gallium nitride compound semiconductor device and manufacturing method

Abstract

A light-emitting element using GaN. On a substrate (10), formed are an SiN buffer layer (12), a GaN buffer layer (14), an undoped GaN layer (16), an Si-doped n-GaN layer (18), an SLS layer (20), an undoped GaN layer (22), an MQW light-emitting layer (24), an SLS layer (26), and a p-GaN layer (28), forming a p electrode (30) and an n electrode (32). The MQW light-emitting layer (24) has a structure in which InGaN well layers and AlGaN barrier layers are alternated. The Al content ratios of the SLS layers (20, and 26) are more than 5% and less than 24%. The In content ratio of the well layer in the MQW light-emitting layer (24) is more than 3% and less than 20%. The Al content ratio of the barrier layer is more than 1% and less than 30%. By adjusting the content ratio and film thickness of each layer to a desired value, the light luminous efficiency for wavelength of less than 400 nm is improved.

Description

technical field [0001] The invention relates to a gallium nitride (GaN) compound semiconductor device and a manufacturing method thereof, in particular to the improvement of luminous efficiency. Background technique [0002] Light-emitting devices in the wavelength range of 370 to 550 nM using nitride semiconductors have been put into practical use. These light-emitting elements mainly use In x Ga 1-x N (0<x<1) is used as a luminescent material. By changing In x Ga 1-x The In component ratio in N changes the emission wavelength by x, and specifically, the larger x is, the longer the emission wavelength becomes. In addition, when the In composition ratio x is changed, the luminous wavelength and luminous efficiency also change together. Specifically, when the In composition ratio x becomes larger, it is due to (1) the difference in lattice constant between GaN or AlGaN that becomes a layer sandwiching InGaN becomes larger and (2) in order to have a high In composi...

AI Technical Summary

Problems solved by technology

Conventionally, for example, the ELO (Epitaxial Lateral Overgrowth) method or the method of growing a light-emitting layer on a sapphire substrate with grooves is used to reduce the dislocation density. It takes time and effort, and as a result, there is a problem that the cost of the light-emitting element increases.

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