FREQUENCY-LOCKED, QUASI-PERIODIC, AND CHAOTIC MOTIONS OF CURRENT-DENSITY FILAMENTS IN A SEMICONDUCTOR-DEVICE

Silicon multilayered devices biased with a de voltage exhibit spontane ous voltage oscillations which are connected with spatial, pendulumlik e oscillations of a current-density filament. When driven with a super imposed sinusoidal voltage, the oscillations of the device voltage sho w frequency locking, quasiperiodicity, and chaos. In order to correlat e the global voltage oscillations with the filament motion spatially r esolved measurements of the filament dynamics have been performed by u sing two different techniques: measurements of the recombination radia tion with a streak camera and measurements of the potential on the dev ice surface between the electrical contacts with an active potential p robe. The experimental results clearly reveal that the various kinds o f voltage oscillations are caused by corresponding frequency-locked, q uasiperiodic, or chaotic filament motions.