Semiconductor structure and preparation method thereof

Abstract

The present application provides a semiconductor structure and a preparation method thereof, including: a substrate; a trench; a bit line contact structure; a bit line structure; a bit line protection structure, the bit line protection structure including a top dielectric layer and a sidewall structure, the top dielectric layer is located on the bit line structure and forms a laminated structure together with the bit line structure; the sidewall structure covers part of sidewalls of the laminated structure on the substrate, the sidewall structure has a first air gap; an isolation pattern structure, the isolation pattern structure has a second air gap, the isolation pattern structure extends along a second direction, the second direction intersects with the first direction, to form capacitance contact hole between the adjacent bit line protection structures and the adjacent isolation pattern structures.