Comparative Study on Graded-Barrier Al_xGa_1−xN/AlN/GaN/Si Metal-Oxide-Semiconductor Heterostructure Field-Effect Transistor by Using Ultrasonic Spray Pyrolysis Deposition Technique

Abstract

Comparative study on a novel Al 2 O 3 -dielectric graded-barrier (GB) Al x Ga 1−x N/AlN/GaN/Si (x=0.22∼0.3) metal-oxide-semiconductor heterostructure field-effect transistor (MOS-HFET) formed by using the ultrasonic spray pyrolysis deposition (USPD) technique has been made with respect to a conventional-barrier (CB) Al 0.26 Ga 0.74 N/AlN/GaN/Si MOS-HFET and the reference Schottky-gate HFET devices. The GB Al x Ga 1−x N was devised to improve the interfacial quality and enhance the Schottky barrier height at the same time. A cost-effective ultrasonic spray pyrolysis deposition (USPD) method was used to form the high-k Al 2 O 3 gate dielectric and surface passivation on the AlGaN barrier of the present MOS-HFETs. Comprehensive device performances, including maximum extrinsic transconductance (g m,max ), maximum drain-source current density (I DS,max ), gate-voltage swing (GVS) linearity, breakdown voltages, subthreshold swing (SS), on/off current ratio (I on /I off ), high frequencies, and power performance are investigated.

Improved Ultraviolet Detection and Device Performance of Al2O3-Dielectric In0.17Al0.83N/AlN/GaN MOS-HFETs

“…This work investigates, for the first time, UV detection based on a gated In 0.17 Al 0.83 N/AlN/GaN metal-oxide-semiconductor heterostructure field-effect transistor (MOS-HFET). The MOS-gate structure was fabricated by growing a 10-nm thick Al 2 O 3 gate-dielectric by using the ultrasonic spray pyrolysis deposition (USPD) [15]- [20] technique. High spectral responsivity (SR) of 360 A/W at 350 nm has been achieved as the device was biased at V GS = 5 V and V DS = 6 V. The present MOS-HFET design has also demonstrated improved breakdown, gate-voltage swing (GVS) linearity, current densities, and power performance.…”

Local Strain and Crystalline Defects in GaN/AlGaN/GaN(0001) Heterostructures Induced by Compositionally Graded AlGaN Buried Layers

“…3 The advantage of this technique has been demonstrated through the fabrication of such devices as deep-UV light emitting diodes, 4−6 lasers, 7,8 p−n junctions, 9−11 and metal-oxide-semiconductor heterostructure field-effect transistors. 12 Recently, nonalloyed ohmic contacts with record low resistance were reported for GaN-based transistors with a graded AlGaN heterojunction. 13 The Λ-shaped profile of Al concentration eliminates the abrupt heterojunction band offsets and provides direct contact to the 2DEG channel.…”

“…Alternatively, it has been found that this polarization field can greatly enhance the efficiency of traditional dopants such as Mg in order to achieve very high carrier concentrations . The advantage of this technique has been demonstrated through the fabrication of such devices as deep-UV light emitting diodes, − lasers, , p–n junctions, − and metal-oxide-semiconductor heterostructure field-effect transistors . Recently, nonalloyed ohmic contacts with record low resistance were reported for GaN-based transistors with a graded AlGaN heterojunction .…”