Epitaxial production method capable of effectively improving P-GaN hole injection layer quality

Abstract

The invention discloses an epitaxial production method capable of effectively improving P-GaN hole injection layer quality. The epitaxial production method capable of effectively improving the P-GaN hole injection layer quality includes the step of sequentially growing a low temperature GaN buffer layer, an unintentional doped GaN layer, an n type electron injection layer, a multiple quantum well active area, a p-GaN hole injection layer and a p type heavy doped contact layer on a substrate, wherein the P-GaN hole injection layer is grown in alternate type nitrogen and hydrogen carrier gas switching environment, doping of magnesium atoms is performed in nitrogen environment, and activation energy of the magnesium atoms is reduced in hydrogen environment. The P-GaN hole injection layer grown in the alternate type carrier gas switching environment can effectively improve efficiency of merging the magnesium atoms into GaN crystal lattices, improves quality of the GaN crystal lattices, reduces work voltage and improves antistatic ability. Simultaneously, activation efficiency of the magnesium atoms is improved, a large quantity of hole carriers are provided, and luminance of LED (light emitting diode) devices is improved by reducing the activation energy of the magnesium atoms.

Description

technical field [0001] The invention belongs to the field of LED epitaxial technology growth, in particular to a method for growing a high-quality p-GaN hole injection layer, which is suitable for the production of high-brightness GaN-based LED epitaxial wafers. Background technique [0002] As a solid-state light source, LED has the advantages of small size, high efficiency, long life, and environmental protection. It is known as the third-generation green energy-saving light source. Although LED has entered the stage of commercial production, in order to further improve the photoelectric performance of LED devices, in There are still many technical difficulties. [0003] One of the main problems is the growth of p-GaN layers of high quality and high hole concentration. In order to ensure the quality of the material and the activation rate of the dopant Mg, the growth temperature of the p-GaN material is generally above 1000°C. However, considering that during the epitaxy...

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Problems solved by technology

However, considering that during the epitaxy process of the LED device structure, the InGaN / GaN multi-quantum active layer is grown in a low-temperature environment of 700-900°C, the subsequent high-temperature environment of p-GaN will inevitably cause serious damage to the InGaN active layer. Decomposition and segregation of In, and finally the luminous performance of the device is greatly reduced

However, when the p-GaN layer is grown at low temperature, it is difficult for Mg atoms to be incorporated into the GaN lattice.

At the same time, due to the deep position of the acceptor energy level of Mg, the activation is difficult, resulting in a relatively low hole concentration. In order to obtain the ideal hole concentration, a large flow of Mg is required.

When Mg is more, in addition to replacing Ga atoms to become Mg Ga In addition to replacement atoms, Mg will also form interstitial atoms in GaN. Due to the small size of Mg atoms, a large number of micro-defects are formed, which in turn makes Mg atoms more difficult to activate. In addition, there is a serious self-compensation effect, which leads to the failure of the device. High voltage and low luminous efficiency

[0004] On the other hand, current research on LEDs points out that Mg atoms in N 2 It is easier to replace Ga atoms in the environment, and become Ga substitution atoms to be incorporated into the GaN lattice, while H 2 The activation energy of Mg grown in the environment is low, and Mg in H 2 The growth in the environment is easier to activate, but the Mg in the H 2 The efficiency of substituting Ga atoms in GaN is low

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