Spray coater and ring-shaped structure thereof

Abstract

A spray coater is used to spray a photoresist on a front surface of a wafer. The spray coater includes a vacuum chuck, a flow guiding ring, and a positioning ring. The vacuum chuck has a top surface and a side surface adjacent to the top surface. The wafer is located on the top surface and protrudes from the top surface of the vacuum chuck. The flow guiding ring is disposed around the vacuum chuck and has a groove. The wafer protruding from the top surface covers the flow guiding ring, and an opening of the groove faces a back surface of the wafer opposite to the front surface. The positioning ring is disposed around the flow guiding ring, such that the flow guiding ring is between the positioning ring and the side surface of the vacuum chuck.

Dependencies are inferred from the claim text.