A planar LED epitaxial structure based on gallium arsenide substrate and its manufacturing method

Abstract

The invention provides a planar LED epitaxial structure based on gallium arsenide substrate and a manufacturing method thereof. The epitaxial structure is composed of the following components from bottom to top: an N-type GaAs substrate layer, an N-type GaAs buffer layer, a P-type GaAs epitaxial layer, an N-type GaAs epitaxial layer, an N-type AlInP restriction layer, an MQW quantum well light emitting layer, a P-type AlInP restriction layer and a P-type GaP window layer. The manufacturing method comprises the steps of (1), supplying a GaAs substrate and cleaning; (2), growing a P-GaAs epitaxial layer; (3), growing an N-GaAs epitaxial layer; (4), growing an N-GaAs epitaxial layer; (5), growing an N-AlInP epitaxial layer; (6), growing an MQW light emitting layer; (7), growing a P-AlInP epitaxial layer; and (8), growing a P-GaP epitaxial layer. According to the planar LED epitaxial structure, electric isolation between the MQW quantum well light emitting layer and the substrate materialis formed by means of a reversal NP junction; and furthermore a relatively thin P-type GaP expansion layer is designed, thereby facilitating relation of an addressing circuit of an LED micro-display matrix, preventing unit pixel damage and falling in performing cutting isolation on the light emitting unit, and keeping integrity of the LED micro-display array.

Description

technical field [0001] The invention relates to a planar LED epitaxial structure based on a gallium arsenide substrate and a manufacturing method thereof, belonging to the technical field of optoelectronics. Background technique [0002] LED display is an active semiconductor electroluminescent device that converts electricity into light. Each light-emitting point in the LED display matrix can be individually driven and controlled by using the principle of dot matrix addressing. An individually controllable light-emitting unit is a pixel; the LED display matrix can be used to display various information such as text, graphics, images, and video signals. The pixels in the commonly used LED display modules are light-emitting diodes that are individually fixed on the circuit board. On the circuit board, there is a circuit that provides power drive and control for each pixel. The space occupied by the circuit distribution makes the display screen more efficient. The distance is...

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Problems solved by technology

[0008] (1) Cutting is used to form the isolation of the light-emitting unit. During the cutting process, there are cracks, contamination, damage, etc. on the material of the light-emitting unit by the cutting knife, so that the light-emitting unit becomes invalid;

[0009] (2) The material is attached to the silicon wafer substrate in the form of adhesion before cutting and isolation. On the one hand, it increases the technical operation steps, and at the same time, there is also the possibility of weak adhesion during the bonding process, which may cause the light-emitting unit to fall off. Sex, reducing the reliability of the product;

"method, cut the P-type layer of the row block to form the independence of the P-type region of the light-emitting unit, but this operation is also easy to cause the GaAs substrate material used as the N-type connection to detach, thereby destroying the matrix. N type row connection

[0011] (4) Due to the cutting method, the depth that the connection of the P-type electrode needs to cross is the thickness of the material itself, generally reaching about 200um, and the width is the width of the cutting blade. This channel not only limits the micro-led The unit size of the display array also makes it extremely difficult to make the connection of the P-type layer by the general metal coating method

[0016] However, when thicker GaP is used for micro-LED display, since the GaP layer is transparent, more side light appears, which makes the unit light-emitting pixel interface of LED micro-display blurred (the light-emitting interface of the pixel is not clear)

On the other hand, the thicker GaP layer 106 and AlInP layer 105 increase the difficulty of isolating the P plane. In the ZL101625981A patent, cutting is used for isolation. Damage to epitaxial luminescent materials such as contamination

[0017] It can be seen from the above prior art background that in the prior art LED epitaxial material structure, since the GaAs substrate is integrally conductive, it is difficult to cut and form independently controllable pixel units of the LED matrix while making the addressing of the single elements in the matrix. circuit

At the same time, due to the thick thickness of the GaP light guide layer, there is also the problem of light crossing on the side of the adjacent unit after cutting.

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