Boron Nitride as a Passivation Capping Layer for AlGaN/GaN High Electron Mobility Transistors

Abstract

We report on the electrical characteristics of AlGaN/GaN high-electron mobility transistors (HEMTs) with hexagonal boron nitride (h-BN) as a passivation capping layer. The HEMTs with h-BN layers showed an increase in current drainage and 103-times reduction in the gate-leakage current compared with those of conventional unpassivated HEMTs. Moreover, the extrinsic transconductance and the pulse responses were improved due to the reduced charge-trapping effect at the surface of HEMTs. From our observations, the h-BN can be used as a passivation capping layer for high-power electronic devices.

Direct Synthesis of Vertical Self-Assembly Oriented Hexagonal Boron Nitride on Gallium Nitride and Ultrahigh Photoresponse Ultraviolet Photodetectors

“…When compared with the situation of zero bias voltage, the photocurrent of the device increased greatly under reverse bias voltage. Taking the most sensitive wavelength (280 nm light) for an example, the highest photoresponsivity was up to 1970.7 mA/W under a −5 V bias voltage (Figure 8c), and the highest detectivity was up to 2.6 × 10 13 Jones under a −3 V bias voltage (Figure 8d). For further research into the photoelectric property of VO-hBN/GaN heterojunction, photocurrent as a function of time under −1 V, −3 V, and −5 V bias voltages was shown in Figure 8a,b under the illumination of 1.5 mW/cm 2 for 255 nm and 280 nm, respectively.…”

“…When compared with the situation of zero bias voltage, the photocurrent o the device increased greatly under reverse bias voltage. Taking the most sensitive wave length (280 nm light) for an example, the highest photoresponsivity was up to 1970.7 mA/W under a −5 V bias voltage (Figure 8c), and the highest detectivity was up to 2.6 × 10 13 Jones under a −3 V bias voltage (Figure 8d). The result of responsivity, shown above, can be determined with Equation ( 7):…”

“…Conventional synthesis strategies of h-BN on GaN applications focus on the transfer of h-BN from that grown on Cu foils by metal-organic vapor phase epitaxy (MOVPE) [11][12][13]. This suffers the disadvantages of contamination and size limitation during sample transfer and stacking.…”

Van der Waals Heterostructure of Hexagonal Boron Nitride with an AlGaN/GaN Epitaxial Wafer for High-Performance Radio Frequency Applications

“…h-BN passivation capping layers, either exfoliated from a crystal h-BN or transferred from h-BN grown by chemical vapor deposition (CVD), have shown promising results. , However, exfoliated h-BN has an obvious drawback in scaling-up for practical device applications. In addition, CVD-grown h-BN on metal substrates requires a polymer-based transfer process, in which wrinkles, tears, and pinholes are easily formed, and etchant and metal residues exist in the h-BN layer, deteriorating the device performance. , Therefore, the realization of wafer-scale and transfer-free h-BN directly formed on AlGaN/GaN HEMT is strongly required for making use of the full advantages offered by h-BN in a practical manner.…”

On the recovery of 2DEG properties in vertically ordered h-BN deposited AlGaN/GaN heterostructures on Si substrate

“…Researchers have transferred few monolayers of h-BN which was grown using chemical vapor deposition at high temperatures (∼1000 °C). 13,14) However, high temperature depositions and transfer techniques are undesirable for largescale and high yield manufacturing. Other methods such as pulsed lasers, 15) ion beams, 16) or magnetron sputtering 17,18) have also shown promising results on the deposition of h-BN films.…”