Lateral profiling of interface traps and oxide charge in MOSFET devices: charge pumping versus DCIV

An improved oxide-charge and interface-trap lateral profiling charge pumping technique (iLPCP) is described. Erase-induced oxide charge and interface traps are investigated in flash EPROM devices. It is shown that the improved technique allows the extraction of profiles in cases where the previous method does not yield satisfactory results. A comparative study of iLPCP and of an existing direct current (DCIV) technique for lateral profiling of interface traps is conducted: both erase- and program-induced interface traps are investigated in flash EPROM devices. The results indicate that 1) iLPCP probes a much bigger portion of the gate region; 2) iLPCP probes a wider energy range; 3) DCIV is more sensitive deep in the channel and thus complements iLPCP.