Deep ultraviolet light emitting device and method of manufacturing deep ultraviolet light emitting device

Abstract

A deep ultraviolet light emitting device includes: an electron block layer of a p-type AlGaN-based semiconductor material or a p-type AlN-based semiconductor material provided on a support substrate; an active layer of an AlGaN-based semiconductor material provided on the electron block layer; an n-type clad layer of an n-type AlGaN-based semiconductor material provided on the active layer; an n-type contact layer provided on a partial region of the n-type clad layer and made of an n-type semiconductor material containing gallium nitride (GaN); and an n-side electrode formed on the n-type contact layer. The n-type contact layer has a band gap smaller than that of the n-type clad layer.

Description

RELATED APPLICATION[0001]Priority is claimed to Japanese Patent Application No.2016-092617, filed on May 2, 2016, the entire content of which is incorporated herein by reference.BACKGROUND1. Field of the Invention[0002]The present invention relates to deep ultraviolet light emitting devices, and, more particularly, to a deep ultraviolet device in which a nitride semiconductor is used and a method of manufacturing such a device.2. Description of the Related Art[0003]Nowadays, semiconductor light emitting devices such as light emitting diodes and laser diodes that emit blue light have been in practical use. Development of light emitting devices that output light having a shorter wavelength, and, more particularly, deep ultraviolet light has been pursued.[0004]Deep ultraviolet light has sterilization capability. Semiconductor light emitting devices capable of outputting deep ultraviolet light have attracted attention as a mercury-free sterilization light source in medical and food proc...

AI Technical Summary

Benefits of technology

This patent describes a method to reduce the contact resistance of the n-side electrode and achieve proper ohmic contact in a light emitting device. By forming the n-side electrode on a n-type contact layer with a smaller band gap than the n-type clad layer, the contact resistance is lowered and the series resistance of the device is reduced. This helps to achieve a low operating voltage. The method includes steps to form a mask, remove the base substrate, and grow the n-type semiconductor material layer on the mask. Overall, this patent provides a solution to improve the performance of light emitting devices.

Problems solved by technology

However, according to the non-patent document 1, the series resistance between the n-side electrode and the p-side electrode in the light emitting device of vertical structure is large and an extremely high operating voltage is necessary to drive the device to produce a high output.

This reduces the series resistance of the light emitting device and reduces an operating voltage.

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