Method for manufacturing semiconductor structure with buried power line and buried signal line

1. A method of fabricating a semiconductor structure, comprising:

providing a substrate having a first top surface;

forming an isolation region in the substrate to surround an active region;

forming a recess in the active region;

disposing a first conductive material within the recess to form a buried power line and a buried signal line;

forming a first circuit layer and a second circuit layer on the first top surface of the substrate, wherein the first circuit layer covers the buried power line and the buried signal line, and the second circuit layer is separated from the first circuit layer; and

forming a cell capacitor over the first circuit layer.

2. The method according to claim 1 , further comprising:

forming a word line structure over the cell capacitor; and

forming an interlayer dielectric to encapsulate the cell capacitor and the word line structure.

3. The method according to claim 2 , wherein after the formation of the interlayer dielectric, a through hole is formed to penetrate the interlayer dielectric and partially expose the second circuit layer.

4. The method according to claim 3 , wherein after the formation of the through hole, a second conductive material is deposited to fill the through hole.

5. The method according to claim 4 , wherein after the formation of the second conductive material, a bit line structure is formed on the interlayer dielectric and over the word line structure.

6. The method according to claim 5 , wherein the bit line structure is electrically coupled to the word line structure and the cell capacitor.

7. The method according to claim 5 , wherein the bit line structure is electrically coupled to the word line structure, the cell capacitor and the first circuit layer.

8. The method according to claim 5 , wherein the second conductive material electrically connects the bit line structure to the second circuit layer.