Strained channel transistors including a PMOS and NMOS device pair to improve an NMOS device performance without substantially degrading PMOS device performance and method for forming the same, the method including providing a semiconductor substrate; forming strained shallow trench isolation regions in the semiconductor substrate; forming PMOS and NMOS devices on the semiconductor substrate including doped source and drain regions; forming a tensile strained contact etching stop layer (CESL) over the PMOS and NMOS devices; and, forming a tensile strained dielectric insulating layer over the CESL layer.