LED flip chip with reflection layer and preparation method thereof

Abstract

The invention provides an LED flip chip with a reflection layer. The LED flip chip comprises a substrate, an N pad and a P pad. An N type layer, a luminescent layer, a P type layer, a reflection layer and a barrier layer are successively superposed on the substrate, and the upper surface of the substrate is etched to form a groove. N electrode holes penetrating though the barrier layer, the reflection layer, the P type layer and the luminescent layer and communicated with the N type layer are formed in the surface of the chip. N lead electrodes electrically connected with the N type layer are formed in the N electrode holes. Reflection ring bands are formed in gaps which are formed between the P type layer and the barrier layer on the edges of the groove and the N electrode holes and / or between the N electrode holes or the N lead electrodes, and are formed on the inner surface of the whole groove. One layer of first insulating layer facilitating mutual insulation is formed on the surfaces and the peripheries of the N lead electrode and the barrier layer. The N pad and the P pad are respectively and electrically connected with the N lead electrodes and the P type layer by means of contact hole formed in the surface of the first insulating layer. The invention further provides a preparation method of the LED flip chip with the reflection layer.

Description

【Technical field】 [0001] The invention relates to the technical field of semiconductor optoelectronic chips, in particular to an LED flip-chip with a reflective layer and a preparation method thereof. 【Background technique】 [0002] Typically, semiconductor layers of different compositions and dopant concentrations are epitaxially grown on sapphire, silicon carbide, or other suitable substrates by metal-organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), or other epitaxy techniques. stacking to fabricate III-nitride light-emitting devices. The stack often includes one or more n-type layers formed on a substrate doped with, for example, Si, one or more light emitting layers in an active region formed on the one or more n-type layers, and One or more p-type layers doped with eg Mg formed on the active region. Forming electrical contacts on the n and p-type regions, III-nitride devices are often formed as inverted or flip-chip devices in which both the N ...

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Problems solved by technology

Moreover, the migration barrier layer 175 made of metal is usually made of a material containing Ti or W. However, the Ti / W material absorbs visible light, so the exposed part after covering the Ag electrode will form a "black edge". light effect

[0005] exist Figure 1A In the device shown, in order to seal the silver contacts with the conductive guard sheet (migration barrier 175), the silver is first etched back from the edge of the mesa, with a gap between the edge 112 of the reflective P-electrode 160 and the edge of the mesa. The strips are called "black edges" 10 because they are not reflective like the silver P-electrode 160, and light absorbed by the black strips may reduce the efficiency of the device

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