Abstract: A clamp holds a semiconductor wafer during an Al reflow process. The clamp is made of a ceramic material, and thereby clamp surface roughening which damages semiconductor wafers and other damaging of the wafer caused by the deformation of the clamp are avoided. A sloped surface of the clamp pad can also reduce the damage on the wafer by reducing the contact area between the clamp pad and the wafer. In addition, the clamp has several features that can reduce heat dissipation from the wafer to outside during the Al reflow. Slots formed on the pad reduce the amount of heat conduction through the clamp, and the polished inner surface of the clamp cap reflects the heat radiated from the wafer back to the wafer.