We present a Metal-Oxide-Semiconductor (MOS) based electro-optic modulator that effectively balances efficiency and speed. The design achieves strong modulation efficiency, and a bandwidth (BW) of 116 GHz, outperforming conventional PN-junction-based device. By replacing ZrO2 as the dielectric material, the device obtains a lower product of half-wave voltage and interaction length VπL to 1.24 V·cm without sacrificing the BW. Further enhancement through a grooved structure aligned with the optical-field maximum drastically reduces VπL to 0.009 V·cm. Although this design introduces some BW narrowing, the device still surpasses the performance of the reported counterparts with comparable VπL values, underscoring the potential of MOS-based architectures for high-performance silicon photonics.