Patent ID: 8512543

Claim:
A method of fluid processing a semiconductor workpiece, comprising: disposing a workpiece holder with a housing capable of containing a fluid, the workpiece holder retaining the workpiece; providing an agitation system connected to the housing and comprising a member disposed within the housing adjacent the workpiece holder; and agitating the fluid by moving the member substantially parallel to a surface of the workpiece with an oscillatory motion, the oscillatory motion being a series of substantially continuous oscillations, wherein each consecutive oscillation of the series includes a first stroke and an opposing second stroke and wherein the first stroke includes a starting point and an ending point, and the second stroke includes a starting point and an ending point, and the ending point of the first stroke coincides with the starting point of the second stroke to thereby define a reversal position, and further wherein the second stroke is not symmetrical to the first stroke with respect to the reversal position such that each oscillation is asymmetrical, and further wherein the starting point of the first stroke is offset from the ending point of the second stroke.