The present disclosure relates to the field of semiconductor technologies, and discloses semiconductor devices and manufacturing methods for the same. A semiconductor device may include: a substrate; a first active region on the substrate; a first gate structure positioned on the first active region; and a first source and a first drain that are positioned in the first active region and respectively on two sides of the first gate structure, where a size of the first drain is larger than a size of the first source. In forms of the present disclosure, because the size of the first drain is larger than the size of the first source, a current from the first drain to the first source is greater than a current from the first source to the first drain, so that the semiconductor device can make a read current relatively low and a write current relatively high in a static random access memory (SRAM), thereby improving a read margin and a write margin.