In {TAIL ~ the absence} of the silicon nitride film on the trench sidewalls, {HEAD ~ the ambient} to be used is preferably any of water vapor, oxygen, nitrogen, hydrogen and N2O or any combination of them 
In
In { TAIL ~ the absence } of the silicon nitride film on the trench sidewalls , { HEAD ~ the ambient } to be used is preferably any of water vapor , oxygen , nitrogen , hydrogen and N2O or any combination of them
REL TAIL TAIL TAIL TAIL TAIL TAIL 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH