Field effect

About: Field effect is a research topic. Over the lifetime, 4018 publications have been published within this topic receiving 92613 citations.

Electrical and photoconductive properties of ion implanted amorphous silicon

Abstract: The results of a systematic study of ion implantation doping in glow discharge a-Si films using groupIII and V substitutional impurities and alkali interstitial ions are described. Implantation doping provides the same range of control of the electrical properties as gas phase doping, but at a lower doping efficiency. The characteristics of an implanted p-n junction, produced by compensation of pre-doped material, are shown. The effect of implantation damage on electrical properties has been investigated by photoconductivity measurements. Finally, the implantation results are used to determine an approximate density of state distribution for a-Si which is compared with field effect data.

Characterization of Pb(Zr, Ti)O3 Thin Films on Si Substrates Using MgO Intermediate Layer for Metal/Ferroelectric/Insulator/Semiconductor Field Effect Transistor Devices

Abstract: Pb(Zr, Ti)O3(PZT)/MgO/Si(001) stacked structures, one of the potential components of ferroelectric-gate field effect trnsistors, have been fabricated and characterized. According to the electrical characterization of MgO/Si structures, MgO thin films prepared on Si substrates at a low growth rate showed a small leakage current of ~10-8 A/cm2 order in an electric field of 1 MV/cm. In C-V measurements of as-grown MgO/Si interfaces, injection-type hysteresis was observed because of crystal defects in the MgO film adjacent to the interface. After oxygen annealing at 400°C, however, it showed no hysteresis and a low interface trap density of the order of 1011 cm-2eV-1 was achieved with no formation of a low-dielectric layer at the MgO/Si interface. These results indicate that MgO thin films are applicable as gate insulators of FETs. After a PZT film was deposited on the MgO/Si structure, the C-V characteristic of the stacked structure showed a ferroelectric hysteresis curve and a low interface trap density of 5×1011 cm-2eV-1. A maximum memory window width of 1.2 V was obtained for the PZT thin film on Si substrate with a MgO intermediate layer.

Modulation of over 1014 cm−2 electrons in SrTiO3/GdTiO3 heterostructures

Abstract: We demonstrate charge modulation of over 1014 cm−2 electrons in a two-dimensional electron gas formed in SrTiO3/GdTiO3 inverted heterostructure field-effect transistors. Increased charge modulation was achieved by reducing the effect of interfacial region capacitances through thick SrTiO3 cap layers. Transport and device characteristics of the heterostructure field-effect transistors were found to match a long channel field effect transistor model. SrTiO3 impurity doped metal–semiconductor field effect transistors were also demonstrated with excellent pinch-off and current density exceeding prior reports. The work reported here provides a path towards oxide-based electronics with extreme charge modulation exceeding 1014 cm−2.

Improved Electrical Stability in the Al Doped ZnO Thin-Film-Transistors Grown by Atomic Layer Deposition

Abstract: Bottom-gate oxide thin-film-transistors (TFTs) with improved electrical stability were fabricated with Al doped ZnO (AZO) channel layers grown by atomic layer deposition (ALD) at a relatively low temperature. The ALD growth at 110°C and the addition of 1-5 atom % Al dopant provided the thin films with reliable semiconducting characteristics, and the TFT devices fabricated with the 1 and 3 atom % AZO films showed a good field effect mobility and on-off current ratio. The transfer curves for the AZO channel TFTs exhibited improved hysteresis loop and positive gate bias stress results compared to those for the pure ZnO TFTs. The improved electrical stability was attributed to the coarsening of the crystal size and the preferred orientation along the nonpolar direction afforded by the addition of Al.

Annealing and light induced changes in the field effect conductance of amorphous silicon

Abstract: We have measured the field effect conductance of α‐Si:H and its dependence on annealing to 180 °C and illumination with white light. We find that illumination produces changes in the field effect conductance which are completely reversed by annealing. Illumination produces a decrease in the off conductance between a factor of 5 and 30 times, together with a shift of the threshold voltage. We interpret the effect of illumination as a modification of the density or occupancy of deep states in such a way that the bulk Fermi level is moved with respect to the conduction band mobility edge. Space‐charge regions can exist at either or both interfaces of the α‐Si:H film and these are very sensitive to interface conditions. The magnitude of the surface band bending is modified by electron trapping in the gate insulator (SiN), which is brought about by bias‐ temperature stressing. Annealing to 180 °C causes the detrapping of excess electrons in the SiN layer, reversing the effect of positive bias‐temperature stres...