Near-Zero Epsilon In MOSFET Structure And Surface Plasmon Polariton Characteristics

Epsilon-near-zero(ENZ)materials and structures have potentials to bring new vitality to fields of optical nonlinearity and optical sensing due to their strong local characteristics of electromagnetic fields.If a sturcutre introducs ENZ in surface plasmon mode,not only can this structure have special optical properties of the surface plasmon(SPP)mode,but also the ENZ characteristics can be used to further enhance the electromagnetic field.However,the current implementations of ENZ material have narrow operating frequency range,and they are limited in tunability and controllability.For these two problems and the effective combination of electron and photon integration,this paper proposes metal oxide semiconductor field effect transistor(MOSFET)structure to realize ENZ.This structure can further enhance the local characteristics of the SPP mode supported by the metal-oxide interface and realize the two-dimensional limitation and regulation of the electromagnetic field through simultaneously controlling the electron concentration and the dielectric constant distribution in the inverse channel under different voltages.The followings are the main work and results of this article:(1)ENZ in the linearly doped Si three-layer plate and the electromagnetic mode characteristics supported by it are studied.The results show that when the dielectric constant of the transition region(the gradual dielectric constant region)has a zero-crossing interface,there is a leak mode in the transition region.The electromagnetic field is confined in the ENZ region along the direction whose dielectric constant is gradual.And the slope of the dielectric constant gradient is larger,the local characteristics are better.(2)The electron concentration and dielectric constant distribution in the inversion channel of MOSFET structure are studied.The effects of oxide layer thickness,source-drain distance,gate voltage and source-drain voltage on electron concentration distribution are analyzed.The MOSFET structure can effectively increase the electron concentration,and the gradual electron concentration and dielectric constant distribution can be obtained in both the x-direction and the y-direction.Moreover,the ENZ wavelength range is extended to ~0.79 ?m-~25 ?m.(3)The electromagnetic mode supported by MOSFET structure is analyzed under the inversion mode,and the results show that the electromagnetic mode supported by theMOSFET while forming ENZ region is essentially a mixture of the conventional two-dimensional SPP mode and the leak mode supported by the ENZ region;the effects of the gate voltage and the source-drain voltage on the distribution of electric field is analyzed.The local characteristics are quantitatively analyzed.Meanwhile,the results show that when the MOSFET structure has the ENZ region,the mode area of this hybrid electromagnetic mode is smaller and the propagation length in infrared band can reach tens or even hundreds of ?m.