Capacitor stack structure and method for forming same

A method for forming a capacitor stack structure, comprising:

• providing a substrate, on which a plurality of first laminated structures arranged in a first direction and a first isolation structure located between adjacent first laminated structures are formed, wherein the first laminated structure comprises first semiconductor layers and second semiconductor layers stacked alternately;
• forming, in the first laminated structures and the first isolation structures, a first trench extending in the first direction, wherein in a second direction, a spacing between the adjacent remaining first semiconductor layers is greater than a spacing between the adjacent remaining second semiconductor layers;
• forming a support structure in the first trench, and removing the first semiconductor layers in the first laminated structure to form a first space;
• and
• forming capacitor structures in the first space, to form a capacitor stack structure;
• wherein the forming first trench extending in the first direction in the first laminated structures and the first isolation structures comprises:
• forming, in the first laminated structures and the first isolation structures, a first sub-trench extending in the first direction;
• and
• etching, in the second direction, a part of each first semiconductor layer in the first sub- trench in the first laminated structures, to form the first trench.