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A method is proposed for calculating the intrinsic noise of a semiconductor sample in the presence of high-order harmonic generation.

A linear and nonlinear analysis of the optical phonon transit-time resonance in bulk wurtzite GaN is carried out using the Monte Carlo method.

Research was conducted to assess the impedance field for noise analysis using various transport models such as the full hydrodynamic model, the drift-diffusion model and the scattered packet approach for the solution of the Boltzmann transport equation. Results demonstrate a good agreement between the models which indicate that the assessment of the impedance field does not need any additional care as regards more conventional operating conditions.

Research was conducted to calculate the transfer impedance field of electronic noise in two-terminal semiconductor structures using a newly developed time-domain formulation method. The model was applied to n+nn+ GaAs structures of overmicron and submicron length at T0=300 K. Results were in good agreement with the noise characteristics that were calculated with the Monte Carlo Particle method which supports the validity of the new approach.

Use of a new hydrodynamic model enables the simulation of the nonlinear and linear response characteristics and hot-carrier transport in InP diodes producing microwave power. Experimental data and Monte Carlo simulations prove the validity of the hydrodynamic model. Periodic evolution and propagation of electron accumulation layers in the diode are the main causes of the microwave power production in the diodes.

A 0.25 micrometer InP diode with an RL circuit generates microwave power with a high-frequency range between 350 gigahertz and 750 gigahertz. Inductance L of the circuit, tunes the generation frequency to this range. Frequencies of 500 gigahertz exhibit the powerful generation frequency. Monte Carlo particle simulation technique for various bias values helps determine noise spectral power densities.

We report on photo-induced terahertz radiation with a high spectral purity generated by a submicron sized InGaAs-based high-electron-mobility transistor. The emission peak is due to the electron-hole pairs photocreated in the transistor channel at the frequency of the beating of two cw-laser sources. The radiation frequency corresponds to the lowest fundamental plasma mode in the gated region of the transistor channel. The observed high emission quality factor at 200 K is interpreted as a result of stream-plasma instability in the two-dimensional electron gas whose appearance is emphasized by the reduction of the velocity relaxation rate with the temperature. [ABSTRACT FROM AUTHOR]

The conditions for microwave power generation at low temperatures under optical phonon emission are analyzed by Monte Carlo simulations of both small- and large-signal responses in bulk zinc blende and wurtzite GaN. As a result of the high optical phonon energy and the strong interaction of electrons with optical phonons in GaN a general improvement on the transit-time resonance and a considerable increase in the maximum generation frequency and power can be achieved in comparison to the widely studied III-V materials such as GaAs and InP. A dynamic negative differential mobility caused by transit-time resonance occurs in a wide frequency range of about 0.05-3 THz and persists in the THz frequency range up to the liquid nitrogen temperature with doping levels up to about 5x10[sup 16] cm[sup -3]. The efficiency of the amplification and generation is found to depend nonmonotonously on static and microwave electric field amplitudes, generation frequency, and doping level so that for each generation frequency there exists an optimal range of parameter values. Under optimal conditions a generation efficiency of about 1% to 2% can be achieved in the 0.5-1.5 THz frequency range. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Monte Carlo particle simulations calculate noise power spectral density and reveal that it arises from shot noise of electrons deposited into layers above the generation threshold frequency. The spectral density corresponds to the maximum generation frequency peak above the threshold frequency and generates real part, negative impedance values of the load resistance. The simulations are applied in microwave generators.

The resonant plasma waves oscillations in several gate-length InGaAs high electron mobility transistors (HEMTs) are measured. A numerical approach is developed that is based on hydrodynamic equations coupled to a pseudo-two-dimensional Poisson solver and a comprehensive spectroscopy of plasma waves in HEMTs is described.

Monte Carlo simulations of small and large signal responses in bulk zinc blende and wurtzite GaN are used to analyze conditions for microwave power generation at low temperatures under optical phonon emission. A considerable improvement in transit-time resonance, maximum generation frequency and power is observed due to high optical phonon energy and strong interaction of electron with optical phonon.