A metal-semiconductor-metal capacitor with embedded two-dimensional charge is designed and fabricated. Capacitance-Voltage characteristics exhibit switchability with a large voltage sensitivity. Maximum and minimum capacitances outperform previous predictions with potential applicability in RFICs and VLSI for reducing the cross-talk among transmission lines and achievement of higher integrations. The device can replace bulky conductors with its negative capacitance feature. The large light sensitivity in the C-V makes this capacitor an ideal candidate for monolithic microwave-photonic integrated circuits.