| 摘要 |
PURPOSE:To prevent the formation of washing residues by sending a steam gas into a dewatering device during an increase in the speed of rotation in a dewatering process taken after a planar solid is washed. CONSTITUTION:A protective oxide film 2 and a silicon nitride film 3 are formed sequentially on an Si substrate 1. Next, the film 3 is etched with a photo resist 4 used as a mask. Then, a high-concentration layer 5 is formed with the resist 4 used as a mask, and then the resitst 4 is removed. Subsequently etching is applied with the films 2 and 3 used as masks, and thereafter a plate-shaped solid thus prepared is subjected to a washing process and then to centrifugal dewatering. While the speed of rotation is increased up to the maximum speed of rotation in this dewatering process, a steam gas is sent into a dewatering device, and after the speed of rotation reaches the maximum, the steam gas is switched over to a nitrogen gas. Next, a selective oxide film (LOCOS film) 7 is formed, and then the films 3 and 2 are etched. According to the centrifugal dewatering method as described above, the humidity in the dewatering device reaches 100% approximately durng the increase in the speed of rotation, and consequently water droplets sticking on an Si wafer are not vaporized. Thus, the formation of washing residues can be prevented. |
