GaN (gallium nitride)-based semiconductor laser and manufacturing method thereof

Abstract

The invention provides a GaN (gallium nitride)-based semiconductor laser and a manufacturing method thereof, belonging to the field of semiconductor lasers. The GaN-based semiconductor laser does not have an electronic barrier layer, thus reducing the working voltage of the laser and prolonging the service life of the laser. For the laser, a quantum cascade radiation layer is arranged between an n-type optical limited layer and an n-type waveguide layer of the laser and utilized to generate infrared radiation when the laser operates, thus realizing ionization of magnesium acceptor impurities in a p-type GaN waveguide layer and a AlGaN optical limited layer, improving carrier concentration in each p-type layer, increasing hole injection current, reducing leakage of electronics from an active area, avoiding introduction of a AlGaN electronic barrier layer and eliminating optical absorption loss caused by the magnesium-doped AlGaN electronic barrier layer, thereby reducing the threshold current of the laser, reducing the working voltage of the laser and prolonging the service life of the laser.

Description

technical field [0001] The invention belongs to the field of semiconductor devices, in particular to a gallium nitride-based semiconductor laser and a manufacturing method thereof. Background technique [0002] As a third-generation semiconductor, gallium nitride (GaN) and its series of materials (including aluminum nitride, aluminum gallium nitride, indium gallium nitride, and indium nitride) are characterized by their large band gap and wide spectral range (covering from ultraviolet to Infrared full band), high temperature resistance and corrosion resistance, has great application value in the field of optoelectronics and microelectronics. GaN-based lasers are very important GaN-based optoelectronic devices. Because the light waves emitted by them are in the blue-violet light band, GaN-based lasers are used in high-density optical information storage, projection display, laser printing, underwater communication, activation of biochemical reagents and It has important appl...

AI Technical Summary

Problems solved by technology

Due to the large ionization energy of acceptor impurities in P-type GaN and AlGaN, such as the ionization energy of magnesium impurities in GaN is between 0.16eV and 0.20eV, such a large ionization energy can make the ionization rate of magnesium impurities less than 1%, and improve the magnesium The doping concentration will cause the decrease of the crystal quality and the increase of the defect concentration, so that the ionized magnesium is compensated by the increased donor, but the hole concentration is reduced.

At the same time, a high doping concentration will reduce the hole mobility. Therefore, the p-type doping of GaN and AlGaN has always been the main obstacle to the improvement of the performance of GaN-based optoelectronic devices.

The hole concentration of the P-type GaN waveguide layer, the P-type AlGaN optical confinement layer and the P-type GaN cladding layer in the GaN-based laser is relatively low, which not only makes the resistivity of the p-type part of the laser relatively large, but also, due to the hole concentration and The mobility is low, and the hole injection current of the double heterojunction laser is significantly smaller than the electron injection current, which causes electrons to leak from the active region and increases the threshold current of the laser.

In order to prevent the leakage of electrons from the active region, Al with a thickness of 20nm is usually introduced between the InGaN / GaN multi-quantum well active region and the GaN waveguide layer. 0.2 Ga 0.8 N electron blocking layer, but Mg-doped Al 0.2 Ga 0.8 The N electron blocking layer has a strong absorption of the luminescence peak of the active region of the InGaN / GaN multi-quantum well, which leads to an increase in the loss of the laser and an increase in the threshold current

At the same time the high resistivity Al 0.2 Ga 0.8 The introduction of the N electron blocking layer further increases the operating voltage of the laser, resulting in a higher operating voltage of the laser

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