Present disclosure provides a method for manufacturing a semiconductor wafer with an epitaxial layer at a front surface of the semiconductor wafer, including providing the semiconductor wafer with a first dopant concentration of a dopant having a first conductivity type, forming a polysilicon layer over the front surface, removing the polysilicon layer from the front surface, and depositing the epitaxial layer at the front surface with a second dopant concentration of the dopant having the first conductivity type under a predetermined temperature. A transition width of the dopant having the first conductivity type across the semiconductor wafer and the epitaxial layer is controlled by the predetermined temperature to be at least about 0.75 micrometer. A semiconductor device and a semiconductor wafer with an epitaxial layer at a front surface of the semiconductor wafer are also disclosed.