Embodiments provide a semiconductor structure and a fabrication method. The method includes: providing a semiconductor substrate, the semiconductor substrate being provided with a plurality of first bit lines extending along a first direction; forming a first transistor array on the semiconductor substrate, the first transistor array including a plurality of first semiconductor pillars; forming first word lines, each of the plurality of first semiconductor pillars being connected to a corresponding one of the first word lines and a corresponding one of the plurality of first bit lines; forming a second transistor array on the first transistor array, the second transistor array including a plurality of second semiconductor pillars, and the plurality of first semiconductor pillars being corresponding to the plurality of second semiconductor pillars one to one; and forming second word lines and second bit lines to form a 2T0C semiconductor structure.