Method for preparing epitaxial wafer of light-emitting diode and epitaxial wafer thereof

Abstract

The invention discloses a method for preparing an epitaxial wafer of a light emitting diode and the epitaxial wafer, and belongs to the field of light emitting diode manufacturing. A plurality of substrates with AlN layers are placed in circular grooves distributed in a plurality of concentric circles in an MOCVD apparatus, and the composition of Al of the AlGaN layers grown on the AlN layers is controlled to increase with the increase of the diameter of the concentric circle. As the diameter of the concentric circle increases, the composition of Al in the AlGaN layers gradually increases, andthe surfaces of the AlGaN layers in the circular grooves change from a state of being recessed toward the bottom surfaces of the centers of the grooves to upwardly convex surfaces away from the bottom surfaces of the grooves. The tendency of this change is opposite to the tendency of the warpage on the surfaces of the substrates. Therefore, the surfaces of the AlGaN layers are more complete, andthe surface warpage of the AlGaN layers counteracts the warpage of the substrate surfaces and the heat transferred to an InGaN / GaN multiple quantum well layer is more uniform, which improves the uniformity of the emission wavelength of the InGaN / GaN multiple quantum well layer, and further improves the luminescence yield of the epitaxial wafer obtained in the same batch.

Description

technical field [0001] The invention relates to the field of light-emitting diode manufacturing, in particular to a method for preparing an epitaxial wafer of a light-emitting diode and the epitaxial wafer. Background technique [0002] Light-emitting diodes are semiconductor diodes that can convert electrical energy into light energy. They have the advantages of small size, long life, and low power consumption. They are currently widely used in automotive signal lights, traffic lights, display screens, and lighting equipment. The epitaxial wafer is the basic structure for making light-emitting diodes. The structure of the epitaxial wafer includes a substrate and an epitaxial layer grown on the substrate. Among them, the structure of the epitaxial layer mainly includes: AlN layer, GaN nucleation layer, undoped GaN layer, N-type GaN layer, InGaN / GaN multiple quantum well layer and P-type GaN layer grown on the substrate in sequence. [0003] When the current epitaxial layer ...

AI Technical Summary

Problems solved by technology

The centrifugal force on the substrate in the circular grooves of each circle is different, which will cause the surface of the substrate on the concentric circles with a smaller diameter to bulge upwards away from the bottom surface of the circular grooves, and the surface of the concentric circles with a larger diameter will bulge upwards. The surface of the substrate is sunken downward toward the bottom of the groove in the center of the circle, and the substrate on the turntable is warped to varying degrees

In addition, due to the warping of the substrate and the epitaxial layer, the heat transferred to the InGaN / GaN multi-quantum well layer will be uneven, which will affect the distribution of In in the InGaN / GaN multi-quantum well layer, thereby affecting the InGaN / GaN multi-quantum well layer. The uniformity of the luminous wavelength, so this setting will eventually make the uniformity of the InGaN / GaN multi-quantum well layer in the epitaxial wafers obtained in the same batch vary greatly, which will affect the luminous pass rate of the epitaxial wafers obtained in the same batch

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