CHARGE TRAP GENERATION IN LPCVD OXIDES UNDER HIGH-FIELD STRESSING

The degradation of low pressure chemical vapor deposited (LPCVD) oxide s, prepared using silane and tetra ethyl ortho silicate (TEOS) as the source, has been investigated under high field stressing, The LPCVD ox ides exhibit enhanced conductivity for the Fowler-Nordheim tunneling c urrent, which is modeled as an effective lowering of potential barrier at the injecting electrode, The charge to breakdown (Q(bd)) Of LPCVD oxides depends on both the deposition chemistry and post deposition an nealing condition, The change in interface-state density (Delta D-it), flatband voltage(Delta V-fb), and gate voltage (Delta\V-g\) during co nstant current stressing are studied to identify the degradation mecha nism, We see a very good correlation between Q(bd) and Delta\V-g\, ind icating that the degradation in LPCVD oxides is dominated by bulk trap generation and subsequent charge trapping, We present a detailed theo retical analysis to substantiate this.