Growth and characterization of horizontally suspended CNTs across TiN electrode gaps.
A technique is proposed to grow horizontal carbon nanotubes (CNTs) bridging metal electrodes and to assess their electrical properties. A test structure was utilized that allows for selective electrochemical sidewall catalyst placement. The selectivity of the technique is based on the connection of the desired metal electrodes to the silicon substrate where the potential for electrochemical deposition was applied. Control over the Ni catalyst size (15-30 nm) and density (up to 3 x 10(11) particles cm(-2)) is demonstrated. Horizontal CNTs with controlled diameter and density were obtained by CVD growth perpendicular to the sidewalls of patterned TiN electrode structures. Electrode gaps with …
Origin of the substrate current after soft-breakdown in thin oxide n-MOSFETs
In this paper is presented an experimental investigation on the origin of the substrate current after soft-breakdown in n-MOSFETs with 4.5 nm-thick oxide. At lower voltages this current shows a plateau that can be explained with the generation of hole-electron pairs in the space charge region and at the Si-SiO2 interface, and to carrier diffusion between the channel and the substrate. At higher voltages the substrate current steeply increases with voltage, due to trap-assisted tunneling from the substrate valence band to the gate conduction band, which becomes possible for gate voltages higher than the threshold voltage. Measurements on several devices at dark and in the presence of light, …
Characterization of soft breakdown in thin oxide NMOSFETs based on the analysis of the substrate current
We have investigated the properties of soft breakdown (SBO) in thin oxide (4.5 nm) nMOSFETs with measurements of the gate and substrate leakage currents using the carrier separation technique. We have observed that, at lower gate voltages, the level of the substrate current exhibits a plateau. We propose that the observed plateau is due to the Shockley-Hall-Read (SHR) generation of hole-electron pairs in the space charge region and at the Si-SiO/sub 2/ interface. At higher voltages, the substrate current steeply increases with voltage, due to a tunneling mechanism, trap-assisted or due to a localized effective thinning of the oxide, from the substrate valence band to the gate conduction ban…