Composite substrate and preparation method thereof, preparation method of light-emitting diode chip

Abstract

The invention discloses a compound substrate, a preparation method of the compound substrate, and a preparation method of a light emitting diode chip with a vertical structure based on the compound substrate. According to the compound substrate, the thickness of a first gallium nitride layer clamped between a first graph layer and a second graph layer is less than the height of first bulge structures, so that the first bulge structures on the first graph layer can be connected with and communicate with the second bulge structures on the second graph layer; and the second bulge structures on the second graph layer are connected together, so that the first graph layer and the second graph layer can form a whole mutually connected graph capable of being corroded with a wet corrosive solution. Once the wet corrosive solution begins to corrode the graph layers from the side face of the compound substrate, the wet corrosive solution can permeate and etch each bulge structure better, so that the wet corrosion stripping of a subsequent epitaxial substrate is facilitated. In addition, the compound substrate can further ensure crystal mass of a subsequent epitaxial layer.

Description

Technical field [0001] The application relates to the field of light emitting diodes, and in particular to a composite substrate and a preparation method thereof. Based on the composite substrate, the application also particularly relates to a method for preparing a vertical structure light emitting diode chip. Background technique [0002] The blue-green light-emitting diode chip includes a horizontal-structure light-emitting diode chip and a vertical-structure light-emitting diode chip. The horizontal-structure light-emitting diode chip uses a sapphire substrate as a substrate, and its thermal conductivity is poor, which affects the reliability of the chip, especially in high-power In the case of high requirements for heat dissipation in lighting, the disadvantages of horizontal structure light-emitting diode chips are more obvious. [0003] The vertical structure of the light-emitting diode chip can use a substrate with good thermal conductivity, such as a silicon substrate, whi...

AI Technical Summary

Problems solved by technology

The use of laser lift-off technology requires the use of expensive laser lift-off equipment on the one hand, and on the other hand, the lift-off is based on laser ablation of the epitaxial layer interface, and the yield of lift-off is not high. The process makes the final grown epitaxial wafer highly warped, and the peeled layers of the entire epitaxial wafer are often not on the same level, which makes it more difficult to focus the laser etching point and lower the yield of peeling

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