The invention provides a self-organized quantum dot semiconductor structure. The quantum dot semiconductor structure includes: a conductive ridge on a substrate; an insulative layer covering the substrate and the conductive ridge, wherein the insulative layer includes a top portion and two sidewalls over the conductive ridge; a semiconductor mechanism of etching back and thermal oxidation, implemented on a semiconductor-alloyed layer set on the insulative layer; a plurality of quantum dots respectively embedded within a plurality of silicon dioxide spacer islands based on the semiconductor mechanism, the quantum dots and the silicon dioxide spacer islands adhered to the sidewalls of the insulative layer; and a plurality of conductive ledges adhered to the silicon dioxide spacer islands, wherein each of the conductive ledges is a portion of an electrode self-alignment to the quantum dot.