Lin-Lin Wang

A Modified 1/

A modified 1/f noise model has been proposed for MOSFETs with an ultra-thin gate oxide layer. It is revealed that as the gate length L deceases, the normalized drain current noise spectra density also decreases, which does not coincide with the regular 1/f noise theory. It is found that the trap-assisted gate leakage affects the drain current 1/f noise, and for the first time, it is demonstrated that the equivalent oxide trap density, the free carrier density, as well as L determine the 1/f noise. A modified quantitative model is then proposed, which can well predict the 1/f noise.

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The Ni(Pt)/Si-cap/SiGe silicidation process has been optimized by modulating the Si-cap layer thickness and a cold Si preamorphization implantation (PAI), which effectively reduces the sheet resistance (Rs). In addition, it is revealed that PAI can obviously increase the Ni(Pt)Si grain size for a lower Rs.

Noise Model for MOSFETs With Ultra-Thin Gate Oxide

The influence of trench oxide on Schottky barrier height (SBH) of TiSix/Si power diode has been investigated in this paper. It is revealed that 4% larger trench oxide coverage will induce 28meV lower SBH for TiSix/Si power diode, which can save ∼5% self-power consumption of the diode when the forward current is set to be 20A. Theoretically, the trench oxide protection structure, which is applied to improve the device reverse characteristics, should not affect the SBH of the diode. However, the diffusion of oxygen atom from the trench oxide into the Ti layer during silicidation process will lead to the formation of TiOx, thus inducing the SBH lowering.

Optimization of Ni(Pt)/Si-cap/SiGe Silicidation for pMOS Source/Drain Contact

The electrical characteristics of Ti/p-SiGe contacts with Ti thicknesses of 3nm and 5nm have been investigated in this paper. TiN was used as a cap layer on Ti. It is observed that as Ti film becomes thinner, Ti/p-SiGe contact resistivity (ρc) increases, but its Schottky barrier height (SBH) decreases, which does not coincide with the regular ρc-SBH dependence. Using TiN/p-SiGe as a control sample, it is concluded that when Ti film is thinned down to nm scale, the contact property is strongly influenced by TiN cap layer.

Influence of trench oxide on Schottky barrier height for TiSix/Si power diode

The scattering mechanisms are investigated for MOSFETs with gate length varying from 1000 nm to 32 nm in this paper. Although the carrier mobility should theoretically be independent on the gate length, using the universal mobility model it is found that as the gate length reduces the Coulombic scattering decreases while the phonon scattering and the surface roughness scattering increase with a decreasing effective mobility. It is revealed that the decreasing effective substrate doping concentration Na related to the reduced threshold voltage Vt is the dominant reason. However, the dominant mechanism varies from the Coulombic scattering for the long gate length to the phonon scattering for the short gate length at medium effective field (about 1 MV/cm).

Observation of contact resistivity independence from Schottky barrier height on heavily doped p-type SiGe

The effect of TiN capping layer on barrier inhomogeneities for TiSix/n-Si Schottky diode is studied by temperature dependent current-voltage (I-V-T) measurements in this paper. The I-V-T curves from 90K to 310K show that the homogeneity of TiSix/n-Si Schottky diode can be obviously influenced by TiN capping layer. A double Gaussian model is employed to characterize the Schottky barrier distribution inhomogenities. It is revealed that the TiN capping layer can degrade the Schottky barrier distribution homogeneity and lower the apparent barrier height of the whole diode.