An integrated circuit contains a transistor with a stress enhancement region on the source side only. In a DeMOS transistor, forming the stress enhancement region on the source side only and not forming a stress enhancement region in the drain extension increases the resistance of the drain extension region enabling formation of a DeMOS transistor with reduced area. In a MOS transistor, by forming the stress enhancement region on the source side only and eliminating the stress enhancement region from the drain side, transistor leakage is reduced and CHC reliability improved.