Manufacturing method for LED epitaxial structure with high luminous efficiency

Abstract

The invention discloses a manufacturing method for an LED epitaxial structure with the high luminous efficiency, and the method comprises the steps: employing the MOCVD technology; sequentially growing a buffering layer, a U-type GaN layer without Si, an Si-doped N-type GaN layer, an active layer, an electron blocking layer and a P-type GaN layer on a substrate; growing a V-type opening angle layer between the N-type GaN layer and the active layer, wherein the V-type opening angle layer is used for guiding the extending direction of a V-type defect, the growth pressure of the V-type opening angle layer is not higher than 300torr, the thickness is not greater than 500nm, and the growth temperature is not lower than 800 DEG C. Therefore, the method can be used for manufacturing the LED epitaxial structure with the high luminous efficiency, and the V-type defect is enabled to extend in a direction where the V-type opening angle layer is located, thereby further increasing the opening angle. Therefore, the method enables the growth speed on a side wall to be higher, reduces a local current, can effectively intercept electrons, inhibits the electron overflow, and improves the luminous efficiency of an LED.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for manufacturing an LED epitaxial structure with high luminous efficiency. Background technique [0002] The GaN-based LED epitaxial structure grown on the sapphire substrate by MOCVD technology is prone to produce more defects during the epitaxial growth process due to the large lattice mismatch; refer to figure 1 , one of the common defects is the V-type defect, which runs through the entire LED epitaxial structure. The reason is that the traditional LED epitaxial structure begins to grow the active layer after the N-type GaN layer is grown. This process from the bottom to the N-type GaN layer will accumulate a lot of stress, so the stress is released when the active layer is grown, resulting in V-type defects, and the adjacent N-type GaN layer structure restricts the V-type defects in the layer direction The extension of , that is, the extension angle of the ...

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Problems solved by technology

[0002] The GaN-based LED epitaxial structure grown on the sapphire substrate by MOCVD technology is prone to produce more defects during the epitaxial growth process due to the large lattice mismatch; refer to figure 1 , one of the common defects is the V-type defect, which runs through the entire LED epitaxial structure. The reason is that the traditional LED epitaxial structure begins to grow the active layer after the N-type GaN layer is grown. This process from the bottom to the N-type GaN layer will accumulate a lot of stress, so the stress is released when the active layer is grown, resulting in V-type defects, and the adjacent N-type GaN layer structure restricts the V-type defects in the layer direction The extension of the V-shaped defect limits the extension angle of the V-shaped defect, resulting in a small opening angle θ

[0003] In fact, the layer that introduces V-type defects will grow in both the sidewall direction a and the vertical direction c, and technicians generally hope that the growth in the sidewall direction a is stronger than the growth in the vertical direction c, because in The growth in the direction a of the side wall is more effective, and the characteristics of the V-shaped defect are: the opening angle θ is small, so the growth in the direction a of the side wall is slow, resulting in a small thickness in the direction a of the side wall, small series resistance, and electron It is easier to pass through the direction a of the side wall, so that the local current increases and a large number of electrons overflow, which greatly reduces the luminous efficiency of the LED

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