Patent ID: 6395086
Filing Date: 2002-05-28
Classification: B05C,H01L

Abstract:
Semiconductor wafer coating apparatus having a chuck for holding a thin circular wafer with one surface of the wafer exposed to receive a coating of a material, the opposite surface being called the wafer back, means including a spindle for spinning the chuck and the wafer, means for dispensing the material onto the exposed surface of the wafer while the spindle is rotating whereby the material flows radially outward across the surface of the wafer and thereby coats the wafer, the material being subject to being slung off from the wafer and to thereby contaminating the wafer back, and a bowl structure with a lower part through which the spindle passes and a side wall part surrounding at least the plane of the wafer,wherein the improvement comprises, a shield for the wafer back having, as a unitary structure, a thin, flat, lower part adapted for attachment to the bowl lower part to be located between the bowl lower part and the chuck, and a cylindrical part extending from the shield lower part, at a radius slightly less than the radius of the wafer, to about the wafer back, whereby improved protection against the deposit of vapor of said material on the wafer back is provided.