A semiconductor structure and method for forming the same. The structure includes multiple fin regions disposed between first and second source/drain (S/D) regions. The structure further includes multiple front gates and back gates, each of which is sandwiched between two adjacent fin regions such that the front gates and back gates are alternating (i.e., one front gate then one back gate and then one front gate, and so on). The widths of the front gates are greater than the widths of the back gates. The capacitances of between the front gates and the S/D regions are smaller than the capacitances of between the back gates and the S/D regions. The distances between the front gates and the S/D regions are greater than the distances between the back gates and the S/D regions.