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