Roughened epitaxial wafer-based electrode color difference improvement method of LED chip

Abstract

The invention provides a roughened epitaxial wafer-based electrode color difference improvement method of an LED chip. The surfaces of a GaN epitaxial wafer in abdicating regions for subsequently preparing electrodes are etched to flat, so that the surface roughness is the same; the electrodes are free of a color difference after being prepared; color difference exception is completely eliminated; the cost caused by the color difference exception is reduced; a transparent conductive layer and the electrodes are subsequently prepared; and the regions are in smooth connection, the current resistance is small, diffusion is fast, the light reflection probability is high and the photoelectricity of the LED chip is also improved to a certain extent.

Description

technical field [0001] The invention relates to the field of LED chips, in particular to a method for improving electrode color difference of LED chips based on roughened epitaxial wafers. Background technique [0002] LED (Light Emitting Diode), light-emitting diode, is a solid-state semiconductor device that can convert electrical energy into visible light, and it can directly convert electricity into light. Compared with ordinary lamps (incandescent lamps, etc.), the emergence of LED lamps has the advantages of energy saving, long life, good applicability, short response time, and environmental protection. [0003] In the manufacturing process of blue and green LED chips, the mainstream method of preparing epitaxial wafers of LED chips is to sequentially deposit N-type layer, light-emitting layer and P-type layer formed by GaN doped with different ions on the sapphire substrate. GaN epitaxial wafers are divided into flat wafers and rough wafers. Flat wafers and coarse wa...

AI Technical Summary

Problems solved by technology

[0008] 2. Epitaxy influence, that is, when preparing the GaN epitaxial layer, the density (hardness) of the N-type layer and the P-type layer has a large difference, and the surface roughness will also have a large difference after ICP dry etching

[0009] 3. Pollution effect. The wafer is polluted before ICP dry etching, which will cause the surface of the N-type layer to be etched uncleanly after ICP dry etching, and chromatic aberration will also occur.

Although this solution effectively solves the problem of electrode color difference, the N electrode only uses a part of the area to conduct current, which will definitely affect the electrical properties of the chip, resulting in high voltage

If the area of ​​the N electrode is increased to reduce the voltage, the production cost will increase (the main material of the electrode is metal gold), and the effect will not be satisfactory.

This way of sacrificing electrical properties to improve chromatic aberration is just a way of tearing down the east wall to make up for the west wall, not an ideal solution

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