placing said substrate into a chemical vapor deposition reactor vacuum chamber and evacuating {TAIL ~ the air} from {HEAD ~ said chamber} 
placing said substrate into a chemical vapor deposition reactor vacuum chamber and evacuating { TAIL ~ the air } from { HEAD ~ said chamber }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD