Hot Electron Noise Research Articles

A generalized expression for diffusion noise and hot electron noise at arbitrary drift velocities

It is demonstrated that the usual form of Nyquist's theorem, extended to include hot electron effects, is valid for arbitrary drift velocities in nondegenerate semiconductors. The same is true for the expression for diffusion noise if the diffusion constant is properly defined from a “spread in drift” experiment.

Hot-electron noise limitations in submillimetre-wave Schottky-barrier mixer diodes

The noise from small-area platinum gallium-arsenide Schottky-barrier mixer diodes has been measured at 4 GHz, to compare high-field (hot-electron) noise in diodes with different doping densities and anode areas. In the present state of technology, submillmmetre-wavelength mixer diodes should be fabricated from gallium arsenide with a doping density of about 1017 cm−3.

Calculation of velocity overshoot, velocity autocorrelation and hot electron noise in semiconductors from the small signal microwave mobility

The small signal behavior of semiconductors under hot electron conditions is modeled as that of a casual, linear, time-invariant system with the small signal mobility as the system transfer function. Using linear system analysis techniques the small signal velocity overshoot is calculated from the mobility thereby establishing a close link between velocity autocorrelation and overshoot. The effect on the transients due to finite collision duration, which can be important in small geometry and high speed semiconductor devices, is demonstrated. This technique allows us to calculate a number of hot electron properties without carrying out involved Monte Carlo computations. Some numerical results for silicon are given as an example.

Deep metal-related centres in germanium : S. J. Pearton. Solid-St. Electron.25 (4), 305 (1982)

The theory of generation-recombination noise in silicon bars and in JFETs is extended to the case in which the devices operate in the hot electron regime. It is shown that Nougier et al.'s measurements at 77°K can at least be partly explained as generation recombination noise; as a matter of fact, the theory can provide an almost perfect match for field strengths between 1000 and 3000 V/cm for g-r noise alone. We believe, however, that some hot electron noise with a similar field dependence as g-r noise is present. One can now understand why Kim, van der Ziel and Rucker found an activation energy of only 63 mV for the noise in silicon JFETs around 77°K.

Observations of electron and hole transport through thin SiO 2 films : S. T. Hsu. RCA Rev.42, 434 (1981)

The theory of generation-recombination noise in silicon bars and in JFETs is extended to the case in which the devices operate in the hot electron regime. It is shown that Nougier et al.'s measurements at 77°K can at least be partly explained as generation recombination noise; as a matter of fact, the theory can provide an almost perfect match for field strengths between 1000 and 3000 V/cm for g-r noise alone. We believe, however, that some hot electron noise with a similar field dependence as g-r noise is present. One can now understand why Kim, van der Ziel and Rucker found an activation energy of only 63 mV for the noise in silicon JFETs around 77°K.

Hot-electron noise generation in gallium-arsenide Schottky-barrier diodes

Measurements of excess (hot-electron) noise in a GaAs Schottky-barrier diode at room temperature are reported. A monotonic decrease with increasing frequency is found. It is concluded that only diode hot-electron noise at intermediate frequency contributes to the excess noise of a mixer.

Hot electron noise and g- r noise in short-channel JFETs

Hot electron noise in short-channel JFETs is measured above 150°K and generation-recombination noise due to donors is measured below 120°K, where it predominates over the first. The hot electron noise increases with increasing V GS - V P for a given temperature T and increasing with decreasing T at a given V GS - V P . The g- r noise in donors increases very rapidly with decreasing temperature and is found to be governed by an activation energy between E 0 and 2 E 0, where E 0 is the activation energy of the donors. The theories of these effects can qualitatively explain the data; for the g- r noise it must be taken into account that the activation energy of the donors decreases with increasing electric field (Poole-Frenkel effect).

Hot electron noise effects in buried channel MOSFETs

Measurements are reported on a 2.0 μmeter buried channel MOSFET. Because of the short channel length, the device showed large hot electron effects. The noise reaches a limiting value above a few MHz; this is attributed to hot electron thermal noise. The parameter α = ( q 2kT )( I eq g m ) is plotted as a function of the absolute temperature T; it increases with decreasing temperature, as expected for hot electron effects.

Hot electron noise in n-InSb

Results of Monte Carlo calculation of hot-electron noise temperature are presented for n-InSb at 85 K. A method for the eatimation of correlation time for velocity fluctuations and calculation of frequency dependence of noise is also given. The results of the calculations are found to agree closely with the available experimental data.

Hot Electon Fluctuations with Displaced Maxwellian Distribution

A theory of hot electron noise in semiconductors is proposed, which is appropriate to the case of strong interelectronic collisions. The effect of interelectronic collisions is taken into account by assuming the displaced Maxwellian distribution and the fluctuations in drift velocity and electron temperature caused by the lattice scattering are treated by the master equation method. The low frequency spectral density of noise current is calculated for the polar optical scattering. It is shown that owing to the electron temperature fluctuation the longitudinal diffusion coefficient becomes much larger than the transverse diffusion coefficient with increase in the electron temperature.

Excess high frequency noise and flicker noise in MOSFETs

The noise parameter α= R n g m , where R n is the noise resistance and g m the transconductance, was measured for n- and p-channel MOSFETs as a function of frequency with the temperature T as a parameter. At lower frequencies α varies as 1/ f, as expected for flicker noise, whereas at higher frequencies α attains a limiting value α ∞ that is larger than expected for thermal noise. Arguments are presented whether this high-frequency noise can be hot electron noise. The flicker noise resistance R mf has a much stronger temperature dependence for n-channel than for p-channel devices; this is related to the energy dependence of the surface state distribution in the forbidden gap.

Generation-recombination noise at 77°K in silicon bars and JFETs

The theory of generation-recombination noise in silicon bars and in JFETs is extended to the case in which the devices operate in the hot electron regime. It is shown that Nougier et al.'s measurements at 77°K can at least be partly explained as generation recombination noise; as a matter of fact, the theory can provide an almost perfect match for field strengths between 1000 and 3000 V/cm for g- r noise alone. We believe, however, that some hot electron noise with a similar field dependence as g- r noise is present. One can now understand why Kim, van der Ziel and Rucker found an activation energy of only 63 mV for the noise in silicon JFETs around 77°K.

Hot electron noise in n-channel JFETs between 150 and 300°K

The noise parameter α T = S I(ƒ) (4kTg m) of n-channel JFETs was measured as a function of the voltage V GS − V P with the temperature T as a parameter between 150 and 300°K. It was found that α T could be approximated by the formula α T ⋍ ( 300 T )α 300 , indicating the presence of hot electron effects.

Calculation on hot-electron noise in semiconductors

Under hot-electron conditions, noise arises both from fluctuations in the carrier velocity and the carrier collision time. The magnitudes of these two contributions are calculated by the Monte-Carlo method for InSb at 77°K.

Transverse Noise of Hot Electrons in n-Type Germanium

This work is an extension of previous analysis of high-field, hot-electron noise in n-type germanium. The previous analysis, developed to explain the author's observations of field-direction (longitudinal) noise, is extended here in an attempt to explain the hot-electron, transverse noise observations of Erlbach and Gunn.In the model adopted, the transverse current fluctuations, resulting from intravalley and intervalley scattering, within the interelectrode volume (electrode area × separation), yield both thermal and intervalley contributions to the noise temperature. For two of the three crystal orientations considered, the intervalley noise is negligible, but in the third case, the two contributions are of the same order.Individual valley currents, populations, and relative intervalley transition rates are calculated from Nathan's analysis, and the Barrie–Burgess theory of high-field transport provides the valley electron temperatures. The intervalley scattering data of Weinreich, Sanders, and White yield absolute values of the intervalley scattering probabilities.Poor agreement is found with the Erlbach–Gunn observations of transverse noise temperature, which may be due to the shunting effect of the portion of the sample exterior to the interelectrode volume.