Patent ID: 7488400
Filing Date: 2009-02-10
Classification: H01L,Y10S

Abstract:
1. An apparatus for etching a wafer by a single-wafer process, comprising: a wafer-chuck which holds a disk-shaped wafer sliced from a silicon single crystal ingot and rotates the wafer in a horizontal plane; a fluid supplying device which supplies an etching fluid on the upper surface of the wafer; a gas injection device which is disposed at the wafer-chuck and injects a gas to the wafer so as to blow off the etching fluid flowing down over the edge of the wafer in the outward radial direction away from the wafer; a first fluid-aspirating device which is disposed at the wafer-chuck and aspirates, together with the gas, the etching fluid blown off from the wafer by the gas injection device; and a second fluid-aspirating device which is placed outside the wafer-chuck and the circumference of the wafer on the wafer-chuck and aspirates the etching fluid blown off from the wafer by the gas injected from the gas injection device and the etching fluid scattered from the wafer by centrifugal force; wherein the gas injection device comprises wherein the first fluid-aspirating device comprises wherein the wafer-chuck comprises where a circumferential face of the cone member is formed so as to have a cone shape such that the diameter of the circumference decreases towards the lower portion, an inner circumferential face of the tapered member is formed so as to have a tapered shape such that the diameter of the inner circumference decreases towards the lower portion, an annular clearance between the circumferential face of the cone member and inner circumferential face of the tapered member serves as the injection channel, and an annular clearance between the circumferential face of the tapered member and the inner circumferential face of the cylindrical member serves as the aspiration channel.