Preparation method of LED

The invention discloses a preparation method of an LED, and belongs to the technical field of semiconductors. The preparation method comprises the following steps: growing an AlGaInP epitaxial layer on the first surface of a GaAs substrate; setting a P-type electrode on the AlGaInP epitaxial layer and setting an N-type electrode on the second surface of the GaAs substrate to obtain a wafer; cutting the first surface of the wafer to form a P-surface cutting gap in the first surface of the wafer; cutting the second surface of the wafer by using an etching technology to form an N-surface cutting gap in the second surface of the wafer; adhering the second surface of the wafer onto an adhesive film, and enabling the first surface of the wafer to be covered with a thin film; splitting the first surface of the wafer to obtain a plurality of independent LED chips; and expanding the adhesive film to separate the LED chips. According to the preparation method, cutting is carried out by using the etching technology on at least one surface, so that the cutting efficiency is greatly improved, and the production cost is reduced.