A semiconductor substrate is disclosed. The semiconductor substrate includes a substrate body having at least an opening formed on a surface thereof, wherein the surface of the substrate body and a wall of the opening are made of an insulating material; and a circuit layer formed on the surface of the substrate body, wherein the circuit layer covers an end of the opening and is electrically insulated from the opening. The opening facilitates to increase the thickness of the insulating structure between the circuit layer and the substrate body of a silicon material to prevent signal degradation when high frequency signals are applied to the circuit layer.