Epitaxial wafer of GaN-based light-emitting diode and preparing method thereof

Abstract

The invention discloses an epitaxial wafer of a GaN-based light-emitting diode and a preparing method of the epitaxial wafer, and belongs to the field of light-emitting diodes. The preparing method includes the steps that a substrate is provided; a buffer layer and an N-type layer sequentially grow on the substrate, an N-type current expanding layer, a multi-quantum-well layer and a P-type layer sequentially grow on the N-type layer, the N-type current expanding layer is a GaN layer adopting a delta doping technology for growth, the doping concentration of the N-type current expanding layer is smaller than that of the N-type layer, starting from one side of the N-type layer, the doping concentration of the N-type current expanding layer is kept unchanged or reduced gradually, and the doping concentration of the portion, adjacent to one side of the multi-quantum-well layer, of the N-type current expanding layer is zero. The current expanding layer grows by adopting the delta doping technology, the carrier concentration is high, compensation is small, and the device is good in heat stability; the undoped GaN layer is introduced into the position close to an active area to ensure transverse expansion of currents and reduce forward voltage drop, the service life is prolonged, and the fact that defects caused by doping extend to the active area and a non-radiative recombination center is reduced.

Description

technical field [0001] The invention relates to the field of light-emitting diodes, in particular to an epitaxial wafer of a GaN-based light-emitting diode and a preparation method thereof. Background technique [0002] LED (Lighting Emitting Diode, light-emitting diode) has the advantages of high efficiency, long life, small size, low power consumption, etc., and can be used for indoor and outdoor white lighting, screen display, backlighting, etc. In the development of this industry, GaN materials It is a typical representative of V-III compound semiconductors, so how to improve the photoelectric performance of GaN-based light-emitting diodes has become a key technology in the semiconductor lighting industry. [0003] The traditional GaN-based epitaxial wafer growth method is to grow an undoped GaN layer, an N-type layer, a multi-quantum well layer and a P-type layer sequentially on the substrate layer. Among them, the N-type layer is the main electron-supply layer, doped ...

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Problems solved by technology

[0005] Although the uniformly doped current spreading layer has a low doping concentration, defects caused by doping (such as reducing the integrity of the crystal, etc.) will still occur, so there are still certain limitations in improving the internal quantum efficiency and reliability of LED devices. And because Si is an amphoteric impurity, when the doping amount in the N-type layer is relatively high, Si atoms will occupy the position of N atoms, forming a self-compensation effect, and the compensation ratio will also increase with the increase of Si doping concentration, Thus affecting the thermal stability of the device

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