AlGaN/GaN metal–insulator–semiconductor high electron mobility transistors (MISHEMTs) using plasma deposited BN as gate dielectric

Abstract

AlGaN/GaN metal–insulator–semiconductor high electron mobility transistors (MISHEMTs) were fabricated on Si substrates with a 10 nm boron nitride (BN) layer as a gate dielectric deposited by electron cyclotron resonance microwave plasma chemical vapor deposition. The material characterization of the BN/GaN interface was investigated by X-ray photoelectric spectroscopy (XPS) and UV photoelectron spectroscopy. The BN bandgap from the B1s XPS energy loss is ∼5 eV consistent with sp2 bonding. The MISHEMTs exhibit a low off-state current of 1 × 10−8 mA/mm, a high on/off current ratio of 109, a threshold voltage of −2.76 V, a maximum transconductance of 32 mS/mm at a gate voltage of −2.1 V and a drain voltage of 1 V, a subthreshold swing of 69.1 mV/dec, and an on-resistance of 12.75 Ω·mm. The interface state density (Dit) is estimated to be less than 8.49 × 1011 cm−2 eV−1. Gate leakage current mechanisms were investigated by temperature-dependent current–voltage measurements from 300 K to 500 K. The maximum breakdown electric field is no less than 8.4 MV/cm. Poole–Frenkel emission and Fowler–Nordheim tunneling are indicated as the dominant mechanisms of the gate leakage through the BN gate dielectric at low and high electric fields, respectively.

Hexagonal Boron Nitride on III–V Compounds: A Review of the Synthesis and Applications

“…The fabricated AlGaN/GaN HEMT with h-BN showed a very promising performance, including a cutoff frequency (f T ) and maximum oscillation frequency (f MAX ) as high as 28 and 88 GHz, respectively, enabled by an effective passivation of surface defects on the HEMT wafer to deliver accurate information with minimized power loss. Tsung-Han Yang et al [54] prepared the AlGaN/GaN MIS-HEMTs with electron cyclotron-resonance microwave plasma chemical-vapor-deposition (ECR-MPCVD), depositing BN as a gate dielectric. The h-BN could effectively reduce the leakage current and improve device performance.…”

Effective Suppression of MIS Interface Defects Using Boron Nitride toward High-Performance Ta-Doped-β-Ga2O3 MISFETs

“…It can be found that the interface of h-BN/β-Ga 2 O 3 is much more smooth and abrupt than that of SiO 2 /β-Ga 2 O 3 (as shown in the white rectangles in the picture). Therefore, we can conclude that the improved electrical properties of Ta-doped β-Ga 2 O 3 MISFET with h-BN gate dielectric are due to the smaller surface roughness, good insulating properties of the h-BN gate dielectric, and low defect density at the h-BN/β-Ga 2 O 3 interface …”

“…Figure 3b shows the output characteristics of the β-Ga 2 O 3 MISFET with h-BN gate dielectric. The much smaller R on of 12.5 Ω•mm and R on,sp of 6.3 mΩ•cm 2 were realized for the h-BN/β-Ga 2 O 3 MISFET, which are characterized using the same method 18 Besides, the energy-band structure of the h-BN/β-Ga 2 O 3 heterostructure was further studied. Figure 4a shows the ultraviolet photoelectron spectroscopy (UPS) spectra of the Ta-doped β-Ga 2 O 3 , from which the corresponding work function and valence band maximum of the Ta-doped β-Ga 2 O 3 are calculated to be ∼4.25 and 10.12 eV, respectively.…”

“…To eliminate the MIS interface defects, the two-dimensional (2D) insulator h-BN was used as the gate dielectric for Ta-doped β-Ga 2 O 3 MISFETs due to its atomically flat and clean surface, ultrawide band gap (∼5.97 eV), and the high dielectric breakdown field (8–12 MV/cm). , Figure a shows the transfer characteristics of the Ta-doped β-Ga 2 O 3 MISFET with h-BN gate dielectric at V DS = 0.5 and 1 V, which exhibits a superior gate control and a high I on / I off of ∼10 8 . Figure b shows the output characteristics of the β-Ga 2 O 3 MISFET with h-BN gate dielectric.…”

Low Threshold Voltage Shift in AlGaN/GaN MIS-HEMTs on Si Substrate Using SiNx/SiON as Composite Gate Dielectric

“…and BN [18]. Various deposition techniques were used to form these insulating gate dielectrics, such as plasma-enhanced chemical vapor deposition (PECVD), low-pressure chemical vapor deposition (LPCVD), in situ metal-organic chemical vapor deposition (MOCVD), and so on [19,20].…”