The wafer/coating/carbon layer unit comprises a workpiece useful in {HEAD ~ the practice} of {TAIL ~ the invention} 
of
The wafer / coating / carbon layer unit comprises a workpiece useful in { HEAD ~ the practice } of { TAIL ~ the invention }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL