Experiments on hot electron noise in semiconductor materials for high-speed devices

A model noise temperature for nonlinear transport in semiconductors

“…Experimental results are obtained from noise measurements on 247-m long and 2.5ϫ10 14 cm Ϫ3 p-doped diodes in the range f ϭ220-850 MHz in the former case 28 and on 7.5-m-long and 10 15 cm Ϫ3 n-doped diodes at f ϭ10 GHz in the latter case. 6 Both measurements are at frequencies suf-ficiently high to get rid of any 1/f and excess noise contribution. In both cases the agreement between theory and experiments is considered to be extremely good in view of the lack of any fitting parameter of the theory.…”

“…To date, there exists no simple way to model T n ( f ) when the system is displaced from equilibrium due to the application of an external electric field, since in general the noise temperature differs from the electronic temperature as well as from the lattice temperature. [6][7][8][9] Calculations can be performed by means of numerical methods such as Monte Carlo simulations [10][11][12] or direct resolutions of the Boltzmann equation. [13][14][15] Monte Carlo simulations are well suited for a kinetic calculation of S v ( f ), 12 but meet difficulties in calculating quantities on a hydrodynamic time scale such as Re͓Ј( f )͔.…”

Γ-Xintervalley-scattering time constant for GaAs estimated from hot-electron noise spectroscopy data

“…The latter can be avoided in short samples; as a result both ⌫-L and ⌫-X transfer contributions to microwave noise are important in GaAs at fields below 30 kV/cm. 6,7 To our knowledge, hot-electron noise measurements of this type have not been performed at the higher electric fields, where the role of L-type valleys is expected to decrease. Consequently, the noise experiments at extremely high electric fields could provide more information on the ⌫-X transfer.…”

“…6,9 The next two thresholds at 0.3 and 0.5 V come from the intervalley transfer of hot electrons. Hot electron velocity fluctuations in short samples at very high fields is contributed quite a bit by the intervalley scattering of ballistic electrons; this ensures the resolution of noise sources due to the L-type and X-type valleys of the conduction band on the voltage scale 6,7 ͑the L and X threshold energies are close to 0.3 and 0.5 eV, correspondingly 3 ͒. Our experimental results show that the maximum contribution to the noise temperature due to the L valleys is essentially lower than that due to the ⌫-X transfer ͑Fig.…”

Competition of shot noise and hot-electron noise in GaAs planar-doped barrier diode

“…The measurements are performed at 10 GHz frequency at room temperature using a high-sensitivity gated radiometric setup. 9 Short 2 s pulses of bias voltage are applied at 125 Hz repetition rate to dissipate the consumed power thus avoiding diode overheat and its thermal breakdown. The forward bias corresponds to a positive potential on the cap layer in respect to the substratum.…”