Fast, Optics-Free Extraction of Interface Trap and Subgap DOS in Amorphous Oxide TFTs Using Single Pulse Charge Pumping

Next-generation ultra-thin floating body (Si/Oxide/MoS.) transistors inherently contain a significant number of interface and bulk defects that alter device performance/reliability. Recent studies show that sub-bandgap (SBG) states cause subthreshold swing ($S S$) saturation at cryogenic temperatures, impacting cryogenic applications in aerospace electronics and quantum computing. In this work, we present a fast, optics-free methodology using single pulse charge pumping (SPCP) to extract interface trap density ($N_{\text {it }}$) and SBG density of states (DOS) in ALD-grown ultrathin amorphous-oxide TFTs. First, we validate the high stability and repeatability of SPCP by multi-pulse charge pumping (MPCP). Second, we embed the SPCP-extracted$N_{\text {it }}$into a physics-based PBTI model, improving the threshold voltage shift ($\Delta {V}_{\text {th }}$) predictions. Finally, we reconstruct SBG-DOS using an SPCP-based extraction framework with hybrid density functional theory (DFT) calculation. We show that post-annealing reduces SBG-DOS in both$\text{In}_{2} \mathrm{O}_{3}$and IGZO, and the SBG-DOS comprises band tail states and oxygen-vacancy-related deep states ($\text{Vo}^{2+}$and$\text{Vo}^{0}$). Overall, our work demonstrates that the SPCP framework enables rapid and reliable${N}_{\text{it}} /$DOS metrology for next-generation transistors.