Manufacturing method of light emitting diode (LED) chip

Abstract

The invention provides a manufacturing method of a light emitting diode (LED) chip. The manufacturing method comprises the following steps: manufacturing a masking layer on a sapphire substrate, and the masking layer is SiO2; manufacturing photoresist patterns on the masking layer; scribing lines by lasers on the exposed masking layer, and formed release stress lines divide the sapphire substrate into a plurality of chip units; removing the photoresist patterns, using mixed liquid of phosphoric acid and sulfuric acid to corrode the side wall of the release stress lines to remove scribed line products; removing the masking layer; growing a GaN-based semiconductor epitaxial layer on the sapphire substrate with the release stress lines on the surface, and the sapphire substrate is obtained according to the above steps; etching each chip unit; manufacturing passivation layers on the surface of the chip, and exposing an N electrode and a P electrode to obtain an LED wafer; and grinding the back face of the LED wafer to be thinner and then obtaining the LED chip by lobes of a lobe machine. According to the manufacturing method of the LED chip, the luminous efficiency of the LED chip can be improved so that the brightness of the LED chip can be effectively improved.

Description

technical field [0001] The invention relates to a method for manufacturing a semiconductor device. Background technique [0002] In recent years, the third-generation wide-bandgap semiconductor materials represented by GaN and SiC have received widespread attention and vigorous research, especially III-V nitride semiconductor materials and their related alloys and heterojunction materials. , High-frequency and high-power devices have great advantages. [0003] At present, high-brightness blue-green LEDs have been successfully developed, but the existence of high threading dislocation density limits the further improvement of the performance of these devices. Therefore, can breakthroughs be made in realizing high-performance LEDs and reducing GaN dislocations Density matters. [0004] GaN-based light-emitting diodes that are commonly used in the world are mainly heteroepitaxy on flat substrates, where the substrate can be sapphire, etc. The disadvantage of this structure is...

AI Technical Summary

Problems solved by technology

[0004] GaN-based light-emitting diodes that are commonly used in the world are mainly heteroepitaxy on flat substrates, where the substrate can be sapphire, etc. The disadvantage of this structure is that because there is no lattice-matched substrate material, GaN-based light emitting Diodes are grown on substrates such as sapphire, silicon carbide, or silicon. The difference in lattice constants causes many dislocations in the epitaxial materials. These defects limit the internal quantum efficiency of light-emitting diodes; light enters from the epitaxial layer When the substrate is used, because the interface is relatively flat, the incident angle of light is relatively small, and the refractive index difference between GaN and the substrate is not large, resulting in low reflectivity, most of the light will escape to the substrate, and cannot be effectively reflected back to the epitaxial layer, greatly Reduced light extraction efficiency of GaN-based light-emitting diodes

For example, Korean patents with publication numbers 1020080087406 and 1020060127623 make a hemispherical mask on sapphire and etch the sapphire to obtain a hemispherical pattern. Although the above method partially reduces epitaxial defects and improves light extraction efficiency, it still has the following disadvantages: Since the refractive index of sapphire is 1.8, which is similar to that of GaN, when light enters the patterned substrate from the epitaxial layer, the reflectivity does not increase significantly, and the improvement of the light output rate of GaN-based light-emitting diodes does not achieve the expected effect