Production method for P type gallium nitride electrode

Abstract

The present invention relates to the preparation method of P-typed gallium nitride electrode, the present invention comprises the procedures that the external Mg on a sapphire substrate is mixed with P-typed gallium nitride kinetosome; a semi-transparent electrode ohm contact layer Ru / Ni is evaporated on the P-GaN kinetosome mixed with Mg through an electronic beam; an adhesion layer Ni is evaporated on the semi-transparent electrode ohm contact layer Ru / Ni through an electronic layer; a layer of high launching mirror Ag is evaporated on the adhesive layer Ni through an electronic beam; a layer of blocking layer Pt is evaporated on the high launching mirror Ag through an electronic beam; a protection layer Au is bonded on the blocking layer Pt so as to prevent the oxidation and the pollution of the metal electrode, thereby completing the preparation of the P-typed gallium nitride electrode.

Description

technical field [0001] The invention is used in the technical field of optoelectronic device manufacture, and specifically relates to a P-GaN electrode body and a preparation method in a GaN-based power light emitting diode (LED). Background technique [0002] In the preparation of GaN-based power LED devices, due to the low doping concentration of P-GaN and the lack of metals or metal systems with a work function higher than that of P-GaN (7.5eV), it is difficult for holes to tunnel through Schottky. Potential barriers make it difficult for P-GaN metal electrodes to form low ohmic contact resistance, and at the same time have high transmission and high reflection, good thermal stability and other properties. [0003] Generally, the traditional P-GaN metal electrode is composed of Ni / Au or transparent conductive oxide (ITO) layer with high reflection mirror Ag and protective layer Au, and the Ni / Au / Ag / Au metallized P-GaN electrode is composed of Mg doped Doped P-GaN layer, ...

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Problems solved by technology

[0003] Generally, the traditional P-GaN metal electrode is composed of Ni / Au or transparent conductive oxide (ITO) layer with high reflection mirror Ag and protective layer Au, and the Ni / Au / Ag / Au metallized P-GaN electrode is composed of Mg doped Doped P-GaN layer, translucent electrode ohmic contact layer Ni / Au, high reflection mirror layer Ag and protective layer Au, although this metal system has low ohmic contact resistance, its resistivity can reach 10-6Ω·cm 2 , but the transmittance of the Ni / Au / Ag / Au metallized P-GaN electrode for 450-460nm is only 73.8%, and the remaining emitted light is absorbed and converted into heat energy inside the electrode, resulting in poor thermal stability of the electrode ; Without the barrier layer Pt, the protective layer is easy to diffuse inside under long-term working conditions or high temperature conditions, resulting in the degradation of the high reflector Ag, reducing the light extraction efficiency of the device, increasing the leakage current and contact resistance, and changing the thermal stability of the electrode. Poor, seriously affecting the long-term reliability of the device

The Ag electrode coated with a high reflection mirror on the ITO is composed of a Mg-doped P-GaN layer, an ITO transparent electrode ohmic contact layer, a high reflection mirror layer Ag and a protective layer. ITO has a small absorption of light (10-4-10-6 amount level), the transmittance for 455-460nm blue light can reach 97%, but the contact resistance between the ITO transparent electrode ohmic contact layer and the Mg-doped P-GaN layer is large, the driving voltage is high and the thermal stability is poor

Therefore, the existing electrode system cannot meet the performance requirements such as low specific contact resistivity, high transmittance, high reflectivity, and good thermal stability of P-GaN electrodes in the preparation process of GaN-based power LEDs.

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