Ge N-Channel MOSFETs with ZrO2 Dielectric Achieving Improved Mobility

High-mobility Ge nMOSFETs with ZrO2 gate dielectric are demonstrated and compared against transistors with different interfacial properties of ozone (O3) treatment, O3 post-treatment and without O3 treatment. It is found that with O3 treatment, the Ge nMOSFETs with ZrO2 dielectric having a EOT of 0.83 nm obtain a peak effective electron mobility (μeff) of 682 cm2/Vs, which is higher than that of the Si universal mobility at the medium inversion charge density (Qinv). On the other hand, the O3 post-treatment with Al2O3 interfacial layer can provide dramatically enhanced-μeff, achieving about 50% μeff improvement as compared to the Si universal mobility at medium Qinv of 5 × 1012 cm−2. These results indicate the potential utilization of ZrO2 dielectric in high-performance Ge nMOSFETs.

Ge N-Channel MOSFETs with ZrO2 Dielectric Achieving the Improved Mobility

High mobility Ge nMOSFETs with ZrO2 gate dielectric are demonstrated and compared against transistors with Al2O3/ZrO2 , ZrO2, and O3 /ZrO 2 gate dielectrics. The Al2O3/ZrO2 provides for dramatically enhanced-effective electron mobility ( μeff ), boosting transistor drive current. Ge nMOSFETs with the Al2O3 /ZrO2 gate insulator achieve a 50% μeff improvement as compared to the Si universal mobility at an inversion charge density ( Qinv ) of 5 × 10 12 cm -2 . An Al2O3 interfacial layer leads to a boost in μeff but increases capacitance equivalent thickness (CET). Utilizing O3 oxidation of Ge surface, Al2O3 -free Ge nMOSFETs having a CET of 1.1 nm obtains a peak μ eff of 682 cm2 /Vs, which is higher than that of the Si universal mobility at the similar Qinv .

Explicit Quantum Drain Current Model for Symmetric Double Gate MOSFETs

In this article, an analytical model for Double gate Metal Oxide Semiconductor Field Effect Transistor (DG MOSFET) is developed including Quantum effects. The Schrodinger–Poisson’s equation is used to develop the analytical Quantum model using Variational method. A mathematical expression for inversion charge density is obtained and the model was developed with quantum effects by means of oxide capacitance for different channel thickness and gate oxide thickness. Based on inversion charge density model the compact model is developed for transfer characteristics, transconductance and C-V curves of DG MOSFETs. The results of the model are compared to the simulated results. The comparison shows the accuracy of the proposed model.