Abstract: A method for preventing cross-contamination of semiconductor wafers during processing comprising covering a surface portion of a support assembly with a process compatible material, engaging a semiconductor wafer with the support assembly, processing the wafer while it is engaged with the support member, and removing the process compatible material from the support assembly after said material is considered to be contaminated. A shield particularly adapted for this process includes a shield portion made from a process compatible material and a process-compatible adhesive for attaching the shield portion to the support assembly.