Influence of Total Ionizing Dose Irradiation on Low-Frequency Noise Responses in Partially Depleted SOI nMOSFETs

Total ionizing dose effect induced low frequency degradations in 130nm partially depleted silicon-on-insulator （SOI） technology are studied by ^60Co γ -ray irradiation. The experimental results show that the flicker noise at the front gate is not affected by the radiation since the radiation induced trapped charge in the thin gate oxide can be ignored. However, both the Lorenz spectrum noise, which is related to the linear kink effect （LKE） at the front gate, and the flicker noise at the back gate are sensitive to radiation. The radiation induced trapped charge in shallow trench isolation and the buried oxide can deplete the nearby body region and can activate the traps which reside in the depletion region. These traps act as a GR center and accelerate the consumption of the accumulated holes in the floating body. It results in the attenuation of the LKE and the increase of the Lorenz spectrum noise. Simultaneously, the radiation induced trapped charge in the buried oxide can directly lead to an enhanced flicker noise at the back gate. The trapped charge density in the buried oxide is extracted to increase from 2.21×10^18 eV^-1 cm^-3 to 3.59×10^18？eV^-1 cm^-3 after irradiation.

Stochastic responses of tumor-immune system with periodic treatment

We investigate the stochastic responses of a tumor–immune system competition model with environmental noise and periodic treatment. Firstly, a mathematical model describing the interaction between tumor cells and immune system under external fluctuations and periodic treatment is established based on the stochastic differential equation. Then, sufficient conditions for extinction and persistence of the tumor cells are derived by constructing Lyapunov functions and Ito＇s formula. Finally, numerical simulations are introduced to illustrate and verify the results. The results of this work provide the theoretical basis for designing more effective and precise therapeutic strategies to eliminate cancer cells, especially for combining the immunotherapy and the traditional tools.

Receiving response of towed line array to the noise of the tow ship in shallow water

The receiving response of towed line array to the noise radiated from the tow ship is investigated through normal mode modeling and computer simulation. The phenomenon that the maximum output of the towed line array is away from the endfire direction towards the tow ship is explained. The result is important for the understanding of the phenomenon and also for the application research concerning the suppression of the noise from the tow ship as well as adequate application of towed array techniques in shallow water.

Performance enhancement of CMOS terahertz detector by drain current

In this paper, we study the effect of the drain current on terahertz detection for Si metal-oxide semiconductor fieldeffect transistors（MOSFETs） both theoretically and experimentally. The analytical model, which is based on the smallsignal equivalent circuit of MOSFETs, predicts the significant improvement of the voltage responsivity Rv with the bias current. The experiment on antennas integrated with MOSFETs agrees with the analytical model, but the Rv improvement is accompanied first by a decrease, then an increase of the low-noise equivalent power（NEP） with the applied current. We determine the tradeoff between the low-NEP and high-Rv for the current-biased detectors. As the best-case scenario, we obtained an improvement of about six times in Rv without the cost of a higher NEP. We conclude that the current supply scheme can provide high-quality signal amplification in practical CMOS terahertz detection.