GaAs/Al 0.4Ga 0.6As triple barrier resonant tunneling diodes with (4 1 1)A super-flat interfaces grown by MBE

Abstract

GaAs/Al 0.4Ga 0.6As triple barrier resonant tunneling diodes (TB-RTDs) have been simultaneously grown on (4 1 1)A and (1 0 0) GaAs substrates mounted side by side on a Mo plate by MBE to confirm the role of the (4 1 1)A super-flat interfaces on their I– V characteristics. Peak-to-valley current ratios ( J p/ J v) obtained for the (4 1 1)A TB-RTDs at 77 K were much higher than those of the conventional (1 0 0) TB-RTDs and the best J p/ J v (37.3) of the (4 1 1)A TB-RTDs was the largest value reported so far for GaAs/AlGaAs TB-RTDs. The J p/ J v values decreased and the peak widths of the current peaks increased with decreasing well width ( L w) from 10 to 4 nm. J p/ J v value of the (4 1 1)A TB-RTD with L w=4 nm, however, still remained 58% larger than that of the (1 0 0) TB-RTD, indicating that the (4 1 1)A super-flat interfaces are very effective to suppress this interface roughness scattering and improve J p/ J v for the TB-RTDs.