A micro LED structure includes a first micro LED chip having opposite first and second sides, a second micro LED chip adjacent to the first side of the second micro LED chip, a third micro LED chip adjacent to the first side of the first micro LED chip, and optical structures respectively over the first micro LED chip, the second micro LED chip and the third micro LED chip. Each of the first, second and third micro LED chip includes a semiconductor stack, a metal pad and a reflective coating layer. The semiconductor stack includes a first semiconductor layer, an active layer in contact with the first semiconductor layer, and a second semiconductor layer in contact with the active layer. The metal pad is in contact with the first semiconductor layer, and the reflective coating layer is disposed around sidewalls of the semiconductor stack.