Present disclosure provides a semiconductor structure including a first transistor and a second transistor. The first transistor includes a semiconductor substrate having a top surface and a first anti-punch through region doped with a first conductivity dopant at the top surface. The first transistor further includes a first channel over the top surface of the semiconductor substrate by a first distance. The second transistor includes a second anti-punch through region doped with a second conductivity dopant at the top surface of the semiconductor substrate. The second transistor further includes a second channel over the top surface of the semiconductor substrate by a second distance greater than the first distance. Present disclosure also provides a method for manufacturing the semiconductor structure described herein.