Method for removing light-emitting diode (LED) chip electrode

Abstract

The invention discloses a method for removing an LED chip electrode, which comprises the following steps of: removing a protective layer covered on the edge of the LED chip electrode; immersing the chip in chrome etching liquid after the protective layer is removed; taking the immersed chip out, washing and drying by air; and adhering a blue membrane or a white membrane on the surface of the air dried chip and then peeling the blue membrane or the white membrane off. The method provided by the invention has very high selectivity, exerts no influences on the other parts of the LED chip structure and retains the conventional indium tin oxide (ITO) layer.

Description

technical field [0001] The invention belongs to the field of LED chip manufacture, and in particular relates to a method for removing LED chip electrodes. Background technique [0002] Light-emitting diode (LED) is a semiconductor device that can convert electrical energy into light energy, and has been widely used in various fields such as urban beautification, indicator display, and indoor lighting. The LED generates photons by injecting current between the two electrodes, and electrons recombine with holes in the quantum well of the LED. [0003] There are roughly three types of substrate materials for LED chips, sapphire, silicon, and silicon carbide. The LED chip with sapphire as the substrate refers to GaN-based materials and the epitaxial layer of the device are mainly grown on the sapphire substrate. The LED chip uses ITO film with good conductivity and light transmission performance as the N-type GaN conductive layer, and the two electrodes are formed by sequentia...

AI Technical Summary

Problems solved by technology

There are two disadvantages in this method: one is that there are too many rework processes, time-consuming and material-consuming; the other is that the ITO conductive film in the chip and the P-type GaN have been annealed, and the GaN surface and ITO have been well integrated , if the original ITO layer is washed off by strong acid immersion during the electrode removal process, it is very likely that the P-type GaN surface at this time will be damaged, and it will not be well integrated with the second evaporated ITO film, eventually resulting in the product The forward voltage is high, especially for roughened epitaxial wafers.

But this method cannot remove the remaining Cr and Pt in the electrode, and its production practicability is not very good

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