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