To realize desired flow velocity distribution without increasing the occurrence of a back flow area and a dead water region by installing a rectification member having a plurality of processing liquid passing holes above a processing liquid supply member and setting the thickness of respective parts so that desired processing liquid velocity distribution is realized as the rectification member.
In a processed object processor cleaning a semiconductor wafer, a processing liquid supply pipe is installed at the base of a processing tank, a rectification board 3 is installed in a place higher than the processing liquid supply pipe, the upper part is made into a processed object storage space and the semiconductor wafer 4 is stored in the processed object space. The rectification board 3 has a plurality of processing liquid passing holes 3a arranged in a grid form for the whole range and thickness is set in accordance with the positions of the processing liquid passing holes 3a so that processing liquid becomes prescribed flow velocity distribution. To put it concretely, the thickness of a center part is set to be small and the thickness of a peripheral edge part to be large so that the upper face of the rectification board 3 becomes a concave form.
ONO MASAO
KI KANNAN
DAIKIN IND LTD