Lattice-Matched p-GaAsSb/n-InP Backward Diodes Operating at Zero Bias for Millimeter-Wave Applications

Abstract

Backward diodes consisting of a heterojunction of p-GaAs 0:51 Sb 0:49 /n-InP, which was lattice matched to an InP substrate, were fabricated for the first time and investigated for their characteristics. The lattice-matched heterojunction is effective in preventing surface defects after crystal growth of the diodes. The backward diodes indicated a curvature coefficient of À17:6 V À1 , which is sufficiently large for zero-bias operation. Voltage sensitivity of 338 V/W was obtained at 94 GHz by use of the circular mesa diode of 2.0 m diameter. Optimum voltage sensitivity of 1603 V/W was estimated when the input impedance was completely matched with the diodes. #

Conductance slope and curvature coefficient of InGaAs/GaAsSb heterojunctions at varying band alignments and its implication on digital and analog applications

“…Backward diode devices to date utilize material that is lattice matched to a binary substrate. 14,[29][30][31][32][33][34][35][36][37] The electron affinity of the material gives a type-II or type-III band alignment, and doping is then used to further tailor the bands, bringing them as close as possible without overlapping. III-V heterojunction TFETs are also primarily lattice matched, 1,3, [9][10][11][12]14,20,25 with the exception of an MBEgrown InAlAs buffer platform demonstrated by Zhu et al 15 In this work, we allow for this additional degree of freedom using lattice mismatch, allowing us to vary band alignment without using doping and to bring the bands as close as possible.…”