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Trapping characteristics of MOS structures with $\beta $ -Ga2O3 substrates and Al2O3 gate dielectrics are evaluated via constant-voltage stress and X-ray irradiation. Traps that affect bias-induced charging are located primarily in the Al2O3 dielectric layer, and are distributed broadly in time and/or energy. Stress-induced flatband voltage shifts are reduced by N2 annealing. Trap-assisted tunneling is shown to be responsible for the observed gate leakage. Hole trapping in the Al2O3 dielectric layer dominates device radiation response. The relatively modest radiation-induced charge trapping observed in these devices is promising for the potential future use of Al2O3/ $\beta $ -Ga2O3 devices in a space environment. [ABSTRACT FROM AUTHOR]

Recent demonstration of aggressively scaled HfO2-based ferroelectric field effect transistors (FE-HfO2-FETs) has illustrated a pathway to fabricate FeFETs that enjoy COMS-compatibility, low power, fast switching speed, scalability, and long retention. One potential issue of this promising technology is its limited endurance, which has been attributed to the degradation of gate stack before the fatigue of polarization in the ferroelectric HfO2 layer. Some associated work has identified charge trapping and trap generation as key villains, but a clear understanding of two aforementioned underlining mechanisms is still missing. In this letter, we initiated this letter to investigate the roles of charge trapping and trap generation in causing endurance failure of FE-HfO2 FETs. [ABSTRACT FROM AUTHOR]

The radiation hardness of AlGaN/GaN high-electron-mobility transistors (HEMTs) is found to improve with increasing GaN channel thickness. Epitaxial MgCaO shows promise as a radiation-tolerant gate dielectric, with only small shifts in operating parameters of metal–oxide–semiconductor HEMTs observed at doses up to 1 Mrad(SiO2). Bias-induced electron trapping and radiation-induced-hole trapping can occur in the MgCaO, depending on the applied bias during stress and/or irradiation. AC transconductance measurements are used to help understand charge trapping in these devices. [ABSTRACT FROM PUBLISHER]

The limited retention time for single-transistor memory cell based on ferroelectric-gated field-effect-transistor (FeFET) has prevented the commercialization of its nonvolatile memory (NVM) option using the commercially available ferroelectric materials, such as strontium bismuth tantalite (SBT) or lead zirconium titanate (PZT), as the gate dielectric. However, the recent advent of the HfO2-based ferroelectric has demonstrated the strong possibility of meeting the NVM requirement of 10-year retention on aggressively scaled FeFETs. This letter will analyze why the retention for HfO2-based ferroelectric (FE–HfO2) is much longer than its PZT or SBT counterparts, based on the two major retention loss mechanisms: depolarization field and charge trapping. [ABSTRACT FROM PUBLISHER]

Charge collection mechanisms are investigated in surface channel GaAs MOSFETs under broadbeam heavy ion irradiation and pulsed two-photon-absorption laser irradiation. The large barrier between the gate dielectric and GaAs eliminates gate conduction current, but there is significant gate displacement current. Charge enhancement occurs because radiation-generated holes accumulate in the substrate, which increases the local electrostatic potential. The increased potential enhances the source-to-drain current, resulting in excess collected charge. The collected charge increases significantly with gate bias, due to the long tails of the charge waveforms that occur for higher gate bias. The collected charge increases with increasing drain bias. [ABSTRACT FROM PUBLISHER]

Charge collection mechanisms in AlGaN/GaN MOS-HEMTs are investigated. Device types include those with no gate oxide, and those with HfO_2 and Al_2O_3 gate oxides. Simultaneous charge collection is observed at the gate and the drain or the source, depending on strike location. Heavy ion data coupled with device simulations show that the introduction of a thin HfO_2 layer in the gate stack introduces only a small valence band barrier, reducing but not preventing collection of holes at the gate in HfO_2-gate devices. Furthermore, using Al_2O_3 gate oxide increases the valence band barrier over that of the HfO_2, to the point where the radiation-induced transient is not detectable. [ABSTRACT FROM PUBLISHER]

Develops a charge pumping method to measure the localized hot-carrier damage in scaled thin-gate metal-oxide-silicon field-effect transistor (MOSFET). Principle and procedure of the method; Derivation of local Vt distribution; Need to study the direct lateral profiles of erase-induced hot-carrier damage; Application of the direct lateral profiling technique to study the hot-carrier-damage induced by various erase voltage configurations.