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SiC metal oxide semiconductor field effect transistors grown on low-doped epilayer channels and on ion-implanted channels with either “as grown” or NO annealed thermal oxides have been electrically characterized. The threshold voltage, effective electron mobility, as well as fixed charge, oxide trap, and interface trap concentrations have been separately obtained using conventional dc sweep, capacitance-voltage (C-V), fast current-voltage (I-V), and low frequency noise measurements. The results show that devices with as grown SiO2 have a much higher density of “slow” bulk oxide traps than devices after postoxidation annealing in NO. The oxide fixed charge density is unaffected by the annealing process. Devices fabricated on ion-implanted channels exhibit only a small increase in the slow bulk oxide trap density and the fixed charge. However, the density of the “fast” interface traps increases dramatically. This suggests that the damage due to the ion-implantation process is mainly interfacial. In contrast to Si devices, this ion-implantation damage is not completely repaired even after annealing. [ABSTRACT FROM AUTHOR]

We have studied the 1/f noise and total-dose response associated with the buried oxides (BOX) of fully depleted nMOS silicon-on-insulators (SOI) transistors. Silicon implantation in the BOX creates a higher density of oxygen vacancy-related defects that reduce the net oxide-trap charge, but increase the back-channel 1/f noise. The 1/f noise of MOSFETs fabricated on silicon-implanted SOI BOX shows little change after 1 Mrad(SiO2) irradiation. Silicon implantation also creates shallow electron traps in the BOX, leading to large bias instabilities. Whether these traps are filed or empty does not significantly affect the 1/f noise. A detailed study of, the 1/f noise, temperature dependence of charge trapping, and radiation response of these SOI nMOSFET transistors shows that charge exchange with shallow electron traps in the BOX occurs mostly via tunneling. Low frequency noise in the double-gate (DG) mode of device operation is also investigated, and found to help mitigate the 1/f noise in fully depleted SOI MOSFETs. [ABSTRACT FROM AUTHOR]

Investigates the back gate noise of irradiated silicon on insulator (SOI) metal oxide semiconductor. Indication of the advantages of SOI; Primary focus of most studies of the effects of radiation on MOS noise; Radiation effects on back gate noise.

Presents a study that compared the temperature and frequency dependence of noise of metal oxide semiconductor transistors before and after radiation exposure and after postirradiation anneal. Background on the low-frequency noise theory; Assessment of threshold-voltage measurements; Analysis of defect-energy distributions.

Presents a study that analyzed density-functional theory calculations suggesting the 1/f noise of metal-oxide-silicon devices is caused by the capture and emissions of electrons at oxygen vacancy defects near the Si-SiO[sub2] interface. Investigation of charge exchange with oxygen vacancies in SiO[sub2]; Analysis of defect microstructures and energetics; Examination of hydrogen-related defects.

There is an intense search for metal gates for the next generation metal-oxide-semiconductor field-effect transistor. The barrier height ([uppercase_phi_synonym]0) at its interface with a gate dielectric must be known to select a suitable metal. In this letter, internal photoemission was used to determine [uppercase_phi_synonym]0 of two technologically important ternary metals, [TaN/TaSiN] and [TaN/TaCN], on a single SiO2 layer and a [HfO2/SiO2] stack. On SiO2, [uppercase_phi_synonym]0 was found to be 3.36 and 3.55 eV at the [TaN/TaSiN] stack/SiO2 and [TaN/TaCN stack]/SiO2 interfaces, respectively. However, on the [HfO2/SiO2] stack, [uppercase_phi_synonym]0 was found be the same at 2.5 eV for both metal stacks. These results are compared to flatband voltage measurements. [ABSTRACT FROM AUTHOR]