Exemplary embodiments provide manufacturing methods for forming a doped region in a semiconductor. Specifically, the doped region can be formed by multiple ion implantation processes using a patterned photoresist (PR) layer as a mask. The patterned PR layer can be formed using a hard-bakeless photolithography process by removing a hard-bake step to improve the profile of the patterned PR layer. The multiple ion implantation processes can be performed in a sequence of, implanting a first dopant species using a high energy; implanting the first dopant species using a reduced energy and an increased implant angle (e.g., about 90 or higher); and implanting a second dopant species using a reduced energy. In various embodiments, the doped region can be used as a double diffused region for LDMOS transistors.