Patent ID: 6522385
Filing Date: 2003-02-18
Classification: G03F

Abstract:
An air shower head for use in showering a wafer stage with air, said air shower head comprising:an annular upper frame defining a hole at the center thereof, and a cavity open at the bottom thereof, said annular upper frame comprising an inner circumferential side wall and an outer circumferential side wall that delimit said cavity, said circumferential inner side wall having a frusto-conical shape and sloping downwardly radially inwardly towards said annular bole so as to define a concavity in the top of the annular upper frame, the thickness of said air shower head becoming greater while moving radially outwardly from a radially innermost end of the inner circumferential side wall of said annular upper frame to a radially outermost end of said inner circumferential side wall; and an annular bottom member mechanically clamped in place at the bottom of said annular upper frame covering said cavity in the annular upper frame, said annular bottom member defining a plurality of pores extending therethrough, when said annular upper frame and said annular bottom member define a space within the air shower head open to said pores so that air introduced into said space under pressure is ejected out of the air shower head through said pores.