INFLUENCE OF AL CONTENT-X ON HOT-ELECTRON NOISE IN ALX GA1-XAS N+NN+ DEVICES - COMPARISON WITH GAAS

Hot electron noise measurements are performed in Si doped AlxGa1-xAs n+ nn+ devices, for three different Al concentrations: x = 0.15, 0.2, 0.25. Noise temperatures are obtained using a pulsed measurement technique as functions of electric field and frequency. Longitudinal diffusion coefficients D(E) are deduced at 4 GHz. Results are analyzed through the scattering mechanisms which greatly affect the electron velocity properties of AlxGa1-xAs materials. Comparisons with n+ nn+ GaAs devices are made.