Method for forming semiconductor structure and semiconductor structure

A method for forming semiconductor structure, comprising:

• providing a semiconductor base with a substrate and a first oxide material layer;
• wherein the first oxide material layer is arranged on the substrate, the first oxide material layer comprises a first region with a bit line structure and a second region located at edge of the first region;
• patterning and etching the first oxide material layer, to remove a part of the first oxide material layer in the first region and a part of the first oxide material layer in the second region;
• wherein oxide line structures are formed on both sides of each bit line structure by a remaining part of the first oxide material layer in the first region, and an annular empty slot structure is formed between a remaining part of the first oxide material layer in the second region and the first region;
• refilling a second material in the first region and in the second region, respectively;
• wherein the second material is different from a material of the first oxide material layer, the second material in the first region forms a plurality of isolation line structures, and the second material in the second region forms an annular dummy isolation layer;
• removing the oxide line structure by patterning and etching, and forming through hole structures each between a bit line structure and an isolation line structure next to the bit line structure;
• and
• forming a conductive material layer in the through hole structures to form a semiconductor structure.