This paper investigates the electrical characteristics and temperature distribution of strained Si/SiGe n-type metal oxide semiconductor field effect transistor (nMOSFET) fabricated on silicon-on-aluminum nitride (SOAN) substrate. This novel structure is named SGSOAN nMOSFET. A comparative study of self-heating effect of nMOSFET fabricated on SGOI and SGSOAN is presented. Numerical results show that this novel SGSOAN structure can greatly eliminate excessive self-heating in devices, which gives a more promising application for silicon on insulator to work at high temperatures.

A strained Si fully depleted SOI MOSFET,which has the advantages of strained Si,high-k gate and SOI structure, is presented in this paper. A two-dimensional analytical model for the threshold voltage in strained Si fully depleted SOI MOSFET with high-k dielectric is proposed by solving Possions equation. Several important parameters are taken into account in the model. Relationships between threshold voltage,Ge Profile and thickness of strained silicon are investigated. The result shows that the threshold voltage decreases with Ge Profile and strained silicon thickness increasing. Relationships between threshold voltage,dielectric constant of high k gate and doping conceration of strained silicon are also investigated. The result shows that the threshold voltage increases with dielectric constant of high-k and doping conceration of strained silicon increasing. SCE and DIBL are analyzed finally,which also demonstrate that this novel device can suppress SCE and DIBL effect greatly.

The low hole mobility restricts the application of Si complementary metal-oxide-semiconductor in high frequency fields. In this paper, the SiGe p-metal-oxide-semiconductor field-effect-transistor (PMOSFET) is studied. By numeric modeling and analysis, the vertical potential distribution of the device is obtained through solving one-dimensional Poisson equations, and the threshold-voltage model is established. The effects of Ge-profile, thickness of Si buffer layer, thickness of Si cap layer and substrate doping on the threshold-voltage are discussed. In SiGe layer, the quantization effect of the potential well in valence band is taken into account. When the gate voltage is large enough, the holes in SiGe channel layer will transit to the Si/SiO2 interface due to band bending and energy level splitting, causing the degradation of device performance. Thus, the hole-sheet-density model in quantum channel of SiGe PMOSFET is established, and the concept of the maximum operating gate voltage is proposed, moreover the channel saturation induced by gate voltage is calculated and analyzed. The results show that the threshold voltage and the maximal operating gate voltage are related to Ge-profile, and a proper increase of Ge-profile can extend the range of the operating gate voltage effectively.

This paper develops the simple and accurate two-dimensional analytical models for new asymmetric double-gate fully depleted strained-Si MOSFET. The models mainly include the analytical equations of the surface potential, surface electric field and threshold voltage, which are derived by solving two dimensional Poisson equation in strained-Si layer. The models are verified by numerical simulation. Besides offering the physical insight into device physics in the model, the new structure also provides the basic designing guidance for further immunity of short channel effect and draininduced barrier-lowering of CMOS-based devices in nanometre scale.

Based on the exact resultant solution of two-dimensional Poisson's equation, the novel two-dimensional models, which include surface potential, threshold voltage, subthreshold current and subthreshold swing, have been developed for gate stack symmetrical double-gate strained-Si MOSFETs. The models are verified by numerical simulation. Besides offering the physical insight into device physics, the model provides the basic designing guidance of further immunity of short channel effect of complementary metal-oxide-semiconductor (CMOS)-based device in a nanoscale regime.