Semiconductor structure and semiconductor memory

A semiconductor structure, comprising:

• a substrate;
• and
• a plurality of active pillars spaced on the substrate, each of the plurality of active pillars extending along a direction perpendicular to the substrate;
• a plurality of word lines spaced on the substrate along a second direction, each of the plurality of word lines extending along a first direction, wherein the first direction intersects with the second direction, each of the plurality of word lines being connected to a given one of the plurality of active pillars positioned in the first direction;
• and in any adjacent two of the plurality of word lines, a groove is provided on a surface of at least one of the two adjacent word lines towards other one of the two adjacent word lines, the groove penetrating through the word line along the direction perpendicular to the substrate;
• and
• a dielectric layer arranged on the substrate and covering the plurality of active pillars and the plurality of word lines;
• wherein an air gap is provided in the dielectric layer positioned between adjacent two of the plurality of word lines.