Patent ID: 7017597

Claim:
A megasonic cleaning apparatus for removing contamination particles on a wafer, comprising: a piezoelectric transducer for generating megasonic energy; and an energy transfer rod installed over the wafer along a radial direction of the wafer for distributing the megasonic energy to cleaning solution over the wafer and for vibrating the cleaning solution, wherein the energy transfer rod is shaped and sized to uniformly distribute energy in the radial direction of the wafer through the cleaning solution to remove the contamination particles from the wafer, wherein the energy transfer rod includes a first end and a second end and the diameter of the first end is smaller than that of the second end, wherein the energy transfer rod further includes an elongated front portion and a rear portion tapered to have a larger cross-section diameter than the elongated front portion, and wherein the energy transfer rod includes a groove formed on the elongated front portion to make energy distribution uniform over the wafer.