GaN film growing on magnesium aluminate scandium substrate as well as preparation method and application of GaN film

Abstract

The invention discloses a GaN film growing on a magnesium aluminate scandium substrate. The GaN film comprises a GaN buffer layer, a GaN nucleation layer, a GaN amorphous layer and a GaN film which sequentially grow on an ScMgAlO4 substrate, wherein a (0001) surface, which deviates from a (11-20) surface by 0.5-1 degrees, of the ScMgAlO4 substrate is an extension surface. The invention fuehrer discloses a preparation method and application of the GaN film. Compared with the prior art, the preparation method has the advantages that the growing process is simple, and the preparation cost is low; and meanwhile, by utilizing an amorphous layer technique, the GaN film prepared by virtue of the preparation method has the characteristics of good crystalline quality, low defect density and the like.

Description

technical field [0001] The present invention relates to GaN films, in particular to GaN films grown on scandium magnesium aluminate (ScMgAlO 4 ) GaN film on substrate and its preparation method and application. Background technique [0002] GaN and III-nitrides are widely used in light-emitting diodes (LEDs), lasers, and optoelectronic devices due to their wide bandgap, stable physical and chemical properties, high thermal conductivity, and high electron saturation velocity. [0003] Currently, GaN-based devices are mainly based on sapphire substrates. The lattice mismatch between sapphire and GaN is as high as 13.3%, which leads to the formation of high dislocation density during the epitaxial GaN film process, which reduces the carrier mobility of the material and shortens the carrier lifetime, which in turn affects GaN-based devices. performance. Secondly, due to the thermal expansion coefficient of sapphire at room temperature (6.63×10 -6 K -1 ) compared with the th...

AI Technical Summary

Problems solved by technology

The lattice mismatch between sapphire and GaN is as high as 13.3%, which leads to the formation of high dislocation density during the epitaxial GaN film process, which reduces the carrier mobility of the material and shortens the carrier lifetime, which in turn affects GaN-based devices. performance

Secondly, due to the thermal expansion coefficient of sapphire at room temperature (6.63×10 -6 K -1 ) compared with the thermal expansion coefficient of GaN (5.6×10 -6 K -1 ) is large, and the thermal mismatch between the two is about 27%; when the epitaxial layer growth is completed, the device will generate a large compressive stress during the process of cooling the device from the high temperature of epitaxial growth to room temperature, which will easily lead to cracks in the film and substrate

Third, due to the low thermal conductivity of sapphire (25W / m.K at 100°C), it is difficult to discharge the heat generated in the chip in time, resulting in heat accumulation, which reduces the internal quantum efficiency of the device and ultimately affects the performance of the device

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