Containers 51, 52, and 53 of nitrogen, phosphine , and silane , respectively, are coupled to tube 37 via pipe 39 under {HEAD ~ the control} of {TAIL ~ flow controllers} 54, 55, and 56, respectively 
of
Containers 51 , 52 , and 53 of nitrogen , phosphine , and silane , respectively , are coupled to tube 37 via pipe 39 under { HEAD ~ the control } of { TAIL ~ flow controllers } 54 , 55 , and 56 , respectively
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH 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 OTH OTH OTH OTH OTH OTH OTH OTH