Method for determining stress effect on a film during scrubber clean

Abstract

A method for determining stress effects, or stress endurance of a film layer coated on a wafer during a scrubber clean process is disclosed. In the method, a wafer having a film layer coated on top is held in a stationary position while a high pressure water jet having a pressure larger than 60 kg/cm2 is scanned across a top surface of the film layer and through a center of the wafer. The total number of stress defects is then counted in the scanning path on top of the film layer as an indication of the stress endurance of the specific coating layer. The invention also discloses a method for scrubber cleaning a wafer surface which is coated with a film layer without causing stress defects in the film by rotating a silicon wafer, which has a film layer coated on top at a suitable rotational speed, and then scanning a water jet across a top surface of the film layer without passing through a center of the wafer. The water pressure utilized for the water jet may be suitably between 50 kg/cm2 and 75 kg/cm2. It is preferred that the water jet does not pass any regions on the top surface of the film layer that is less than 2 mm from the center of the wafer.

Dependencies are inferred from the claim text.