Patent ID: 10867798

Abstract:
A photoresist is applied to a front surface of a semiconductor wafer rotating at a predetermined rotational speed and a photoresist film having a predetermined thickness is formed and dried. Next, a chemical is dripped while the semiconductor wafer is rotated at the predetermined rotational speed or less, whereby an edge part of the photoresist film is dissolved and removed by the chemical while the predetermined thickness of the photoresist film is maintained. A predetermined pattern is transferred to the photoresist film by exposure and development. After the development, without performing UV curing or post-bake, the photoresist film is used as a mask and helium irradiation having a range of 8 μm or greater from the front surface of the semiconductor wafer is performed. Thus, a predetermined impurity may be implanted with good positioning accuracy in a predetermined region, using the photoresist film as a mask and cost may be reduced.