Negative differential resistance characteristics of GaN-based resonant tunneling diodes with quaternary AIInGaN as barrier

摘要

AlInGaN lattice-matched to GaN is proposed as a barrier for double-barrier single quantum well structure resonant tunneling diodes (RTDs), and it achievesnearly strain-free RTD with low In composition and thereby relatively high manufacturability. Compared with the lattice-matched ternary Al0.83In0.17N/GaN RTD, three lattice-matched InAlGaN/GaN RTD samples exhibit peak current density J(P) over 20 times larger than that of the lattice-matched ternary RTD in numerical simulations. Simultaneously, two shallow defect levels (E-1 = 0.351 eV, E-2 = 0.487 eV) are considered at the RTD heterointerface to reveal the I-V characteristics under different defect densities. Negative differential resistance characteristics of the three quaternary RTDs are still available even though the defect density is up to similar to 10(18) cm(-3), while that of the lattice-matched ternary RTD almost disappears when the defect density is similar to 10(17) cm(-3) as a result of the lager ionization rate. Further, we introduce a deep-level defect E-t = 1 eV at the heterointerface and perform multiple forward voltage sweeps. Simulations show that the quaternary RTD samples have better reproducibility in spite of the defect density being 100 times larger than that of the lattice-matched ternary RTD. This work illustrates that InAlGaN can provide greater flexibility for the design and fabrication of GaN-based RTDs.