High Speed InAs/AlSb and In0.53Ga0.47As/AlAs Resonant Tunneling Diodes

ABSTRACTWe report a comparison of InAs/AlSb and In0.53Ga0.47As/AlAs resonant tunneling diodes (RTDs) for high speed switching applications. Theoretical simulations are performed for both heterostructure systems using a two band tunneling model, which includes the effects of strain and band bending. Experimental peak current densities are observed to agree well with the calculated values over the range 1×104 A/cm2 to 5× 105 A/cm2. In both types of structures, the maximum peak current density (directly related to switching speed) is determined by device heating. In this regard, InAs/AlSb RTDs are found to be slightly superior to In0.53Ga0.47As/AlAs RTDs due to the low contact and series resistances of InAs. However, higher peak-to-valley ratios and swing voltages are obtained in the In0.53Ga0.47As/AlAs devices up to their maximum attainable peak current density (3.1×105 A/cm2 in this study). Both heterostructure systems yield RTDs with estimated switching times near 1 ps.