Micro led chip and preparation method thereof

A Micro LED chip, which is prepared by the a method comprising:

• providing a substrate;
• forming a buffer layer on a surface of the substrate;
• and
• forming a plurality of pixel columns arranged at intervals on a side of the buffer layer away from the substrate, wherein the pixel columns comprise a blue pixel column, a green pixel column, and a red pixel column, and forming the pixel columns comprises:
• epitaxially growing a plurality of first n-type doped GaN layers arranged at intervals on the side of the buffer layer away from the substrate;
• growing a first barrier layer on a surface of the first n-type doped GaN layers away from the substrate;
• growing a quantum well structure layer on a surface of the first barrier layer away from the substrate;
• sequentially growing a blue quantum well light-emitting layer, a green quantum well light-emitting layer, and a red quantum well light-emitting layer on a surface of the quantum well structure layer away from the substrate to obtain the red pixel column;
• etching and removing the red quantum well light-emitting layer and the green quantum well light-emitting layer corresponding to a position of the blue pixel column to obtain the blue pixel column;
• and
• etching and removing the red quantum well light-emitting layer corresponding to a position of the green pixel column to obtain the green pixel column.