Because {TAIL ~ stainless steel} is the material typically used for the boat for PSG deposition, the linear coefficient of {HEAD ~ thermal expansion} of the boat is significantly greater than that of PSG 
Because { TAIL ~ stainless steel } is the material typically used for the boat for PSG deposition , the linear coefficient of { HEAD ~ thermal expansion } of the boat is significantly greater than that of PSG
OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH 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 OTH OTH