The contact is made by etching {TAIL ~ the film} with an acidic solution and thereafter treating the etched surface with {HEAD ~ an alkaline solution} 
The contact is made by etching { TAIL ~ the film } with an acidic solution and thereafter treating the etched surface with { HEAD ~ an alkaline solution }
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD