SEMICONDUCTOR STRUCTURE AND METHOD FOR MANUFACTURING THE SAME

A method for manufacturing a semiconductor structure includes preparing a semiconductor substrate which includes a memory cell region and a peripheral circuit region; forming a buried word line in the semiconductor substrate in the memory cell region; forming a bit line structure over the semiconductor substrate in the memory cell region; forming a dielectric layer in the peripheral circuit region and the memory cell region; forming a first opening in the dielectric layer in the memory cell region; filling a silicon filler in the first opening; forming a second opening in the dielectric layer in the peripheral circuit region; forming a sidewall spacer over a sidewall of the second opening; recessing the silicon filler to form a silicon plug, wherein the silicon plug fills a lower portion of the first opening; and forming a first metal silicide over a top surface of the silicon plug, and concurrently forming a second metal silicide in a lower portion of the second opening.