STRUCTURE AND FORMATION METHOD OF SEMICONDUCTOR DEVICE STRUCTURE

摘要

A semiconductor device structure and a forming method thereof are disclosed. According to several embodiments, the semiconductor device structure and the forming method thereof are provided. According to the present invention, the semiconductor device structure comprises: a gate stack on a semiconductor substrate; source/drain structures adjacent to the gate stack; and cap elements on the source/drain structures. Each of the cap elements has an upper surface and a side surface. A width ratio of the upper surface to the side surface of each cap element is in the range of 0.125 to 1.