A method of manufacturing vertical LED chips to realize the reuse of sapphire substrates

Abstract

The invention provides a vertical LED (light-emitting diode) chip preparation method capable of realizing the repeated utilization of a sapphire substrate. According to the method, a sacrificial layer with a strip-shaped trench is prepared on a sapphire substrate with a single polished surface; a GaN buffer layer grows at the bottom of the trench to expose the sapphire substrate; an un-doped GaN layer transversely grows on the surface of the sacrificial layer with a buffer layer inside the trench as a basis; an N-type GaN layer, a quantum well layer and a P-type GaN layer sequentially grow on the surface of the un-doped GaN layer; and metal reflecting layer and a metal bonding layer are prepared on the surface of the P-type GaN layer. The metal bonding layer is prepared on a silicon wafer substrate, and then the metal bonding layer and the silicon wafer substrate are bonded together. After the bonding process, the sacrificial layer is corroded by the HF solution, so that the sapphire substrate with the single polished surface is removed. Finally, the sapphire substrate is subjected to CMP (chemical mechanical polishing) treatment, so that the repeated utilization of the sapphire substrate is realized. Based on the above method, the repeated utilization of the substrate for preparing vertical LED chips is realized, and the production cost is saved.

Description

Technical field [0001] The technical scheme of the present invention relates to a method for preparing a vertical LED chip suitable for reusing a sapphire substrate, and belongs to the field of optoelectronics. Background technique [0002] Traditional LED chips use sapphire as a substrate to grow a GaN epitaxial layer. The sapphire substrate has poor thermal conductivity, which greatly restricts the heat dissipation of the LED. At the same time, its basically non-conductive nature leads to the need to sacrifice part of the light-emitting layer when preparing the N electrode, which has a great impact on the brightness of the LED. [0003] As people’s requirements for LED integration and luminous brightness increase, traditional LED chips can no longer meet the requirements. Therefore, substrate transfer technology is used to replace sapphire with vertical LEDs with good conductivity and high thermal conductivity such as Cu and Si substrates. Chips are currently the focus of resear...

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Problems solved by technology

CN102610578A A matrix type sapphire substrate and a preparation method thereof, the method uses a double-polished sapphire substrate, prepares a matrix on the C surface of the substrate, and then grows epitaxy to improve the growth quality of the GaN epitaxial layer. The double-polished sapphire The substrate is easy to lift off by laser, but the local high temperature generated during the stripping will cause damage to the surface of the sapphire substrate, which is not conducive to reuse, and the GaN film will be damaged due to the rapid release of stress during the stripping; the laser stripping sapphire substrate technology is adopted in the industry, and The sapphire substrate will be ground and thinned before peeling off, and the peeled sapphire substrate can only be treated as waste, resulting in great waste

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