Patent ID: 6165267
Filing Date: 2000-12-26
Classification: B05C,B08B,H01L,Y10S,Y10T

Abstract:
An apparatus for spin coating, comprising:a) a chuck adapted to hold and rotate a wafer, such that said wafer defines a plane and an outer edge;b) a catch cup substantially surrounding said outer edge, and defining an exhaust port in proximity to said outer edge; andc) an exhaust duct extending from said exhaust port away from said outer edge to an external exhaust, wherein said exhaust duct defines an exhaust gas flow path, and wherein said exhaust duct has a cross sectional area measured substantially orthogonal to said exhaust gas flow path, and wherein said cross sectional area decreases from a maximum near said plane to a reduced value at a second point along said exhaust gas flow path, and wherein said exhaust duct comprises an outer wall distal from the rotational axis of said wafer, and wherein said outer wall comprises a first portion substantially perpendicular to said plane and a second portion substantially parallel to said plane, and wherein said first portion forms a connection with said second portion in proximity to said outer edge with a radius of curvature at least 1/4 the height above said plane of said connection.