Integration of a resonant-tunneling structure for microwave applications

Abstract

We report the realization of very small area resonant tunneling diodes (RTD's) for integrated microwave applications. Diodes with areas down to 3×3 μm2 were fabricated with the necessary coplanar lines for microwave wafer probing. Peak to valley ratios up to 3.5 with peak current densities ranging from 0.6 A/cm2 to 1.5 kA/cm2 have been achieved for Al0.4Ga0.6 As/GaAS double barrier heterostructures grown by MBE on Semi-Insulating substractes. Reflection gain versus frequency measurements in the 1.5-26.5 GHz range, at room temperature, were performed. The smaller devices exhibit a maximum cut off frequency for the negative differential resistance of 18 GHz. For high current versions, we expect significant increase in frequency limit

Effects of spacer layers on the Wigner function simulation of resonant tunneling diodes

“…This correlates perfectly with the higher level of peak current obtained for structure B, as one would expect because of the higher resonant voltage for this structure. Although qualitatively, the previous simulations explain the experimental results of other authors, 23 showing the different resonant voltage level obtained under direct and reverse polarization of asymmetrically doped RTDs.…”

Quantum Monte Carlo simulation of resonant tunneling diodes based on the Wigner distribution function formalism

“…Among these devices, resonant tunneling diodes ͑RTD's͒ have received much attention due to their potential applications as microwave sources and to high-speed electronics. 1,2 To predict and explain device behavior, as well as to aid in RTD-based circuit design, the development of efficient and reliable simulation tools is of great importance. In this regard, the nonequilibrium Green function theory due to Lake et al 3…”