Quantitative analysis of the trapping effect on terahertz AlGaN/GaN resonant tunneling diode

Abstract

We report on a simulation for terahertz aluminum gallium nitride (AlGaN)/gallium nitride (GaN) resonant tunneling diode (RTD) at room temperature by introducing deep-level defects into the polarized AlGaN/GaN/AlGaN quantum well. Results show that an evident degradation in negative-differential-resistance characteristic of RTD occurs when the defect density is higher than ∼106 cm−2, which is consistent with the measurements of the state-of-the-art GaN RTDs. At around 300 GHz, the simulation for a RTD oscillator also demonstrates evident decreases of rf power and efficiency because of the electron trapping effect.

Reliable GaN-based resonant tunneling diodes with reproducible room-temperature negative differential resistance

“…Our experimental findings agree well with recent theoretical studies pointing out that dislocation densities lower than ~10 6 cm -2 are essential for reliability 27 . Experimentally improving the reliability of the NDR required further material engineering to eliminate the piezoelectric fields and hence the band-bending related 2D electron gas at the double barrier hetero-interfaces 28 .…”

Highly repeatable room temperature negative differential resistance in AlN/GaN resonant tunneling diodes grown by molecular beam epitaxy

“…This kind of feature can be utilized in a vast number of applications ranging from self-oscillators to logic and memory. 2 III-nitride RTDs [3][4][5][6][7][8][9][10][11][12][13][14] have attracted a great deal of interest in recent years as they have potential to increase the power output and operating temperature of RTDs due to the large band offsets available in pseudomorphic and III-nitride heterojunctions ($2 eV for AlN/GaN). Subsequently, intraband tunneling could enable a new class of tunneling injection devices.…”

Coherent vertical electron transport and interface roughness effects in AlGaN/GaN intersubband devices

“…[13][14][15][16][17] Another important characteristic of AlGaN/GaN heterostructures is the large built-in electrostatic fields due to both spontaneous and piezoelectric polarization which alter the current-voltage (I-V) characteristics significantly. Recent advances in growth technology have reduced threading dislocation densities substantially to allow repeatable measurement of wurtzite and cubic AlGaN RTDs [18][19][20][21][22][23] and sequential tunneling devices. 24,25 Furthermore, NDR features have also been demonstrated in defect-free nanowires.…”