Temporal and Thermal Stability of Al₂O₃-Passivated Phosphorene MOSFETs

Surface and interfacial study of half cycle atomic layer deposited Al2O3 on black phosphorus

“…These properties indicate that black-P is a promising candidate for electronic and optoelectronic device applications. However, the strong hydrophilic [6,7] and photo-oxidative [4] properties of black-P raise important concerns regarding its chemical and physical stabilities during the device fabrication. Recent work by Wood et al [8] and Castellanos-Gomez et al [7] has shown that water droplets and oxidation can be detected on the surface of black-P after several hours of ambient exposure, and the surface is more severely oxidized if exposed for longer than 1 week, causing etching of some thin black-P flakes.…”

“…Thus, it is critical to develop an efficient isolation or passivation layer for the black-P surface to maintain intrinsic electronic properties for a longer time. Typical black-P based transistors use ALD of Al 2 O 3 [2,6,10] or HfO 2 [11] as a dielectric layer for electrical isolation. Work by Luo et al [6] specifically mentioned that a few-layer black-P metal oxide semiconductor field-effect transistor (MOSFET) with Al 2 O 3 passivation can be ambient stable as long as 100 h. However, the detailed identification of the interfacial chemical states resulting from ALD Al 2 O 3 /black-P is unclear and important.…”

“…Typical black-P based transistors use ALD of Al 2 O 3 [2,6,10] or HfO 2 [11] as a dielectric layer for electrical isolation. Work by Luo et al [6] specifically mentioned that a few-layer black-P metal oxide semiconductor field-effect transistor (MOSFET) with Al 2 O 3 passivation can be ambient stable as long as 100 h. However, the detailed identification of the interfacial chemical states resulting from ALD Al 2 O 3 /black-P is unclear and important. In this study, in situ monochromatic XPS characterization of the interfacial chemistry was carried out to understand the evolution of interfacial interaction, chemistry and nucleation of Al 2 O 3 after ''half cycle'' ALD Al 2 O 3 on the native and the freshly exfoliated black-P surfaces, separately.…”

Monolayer transition metal dichalcogenide and black phosphorus transistors for low power robust SRAM design

“…3(b). The contact resistivity and parasitic capacitance for TMDCFETs are 5.4×10 3 Ωμm 2 and 0.05 aFμm −2 , and for BPFETs with Ni contacts, the values are 1.75×10 3 Ωμm and 22aFμm −1 , respectively [20][21][22][23]. Thus, effective contact resistance of nanoscale devices is in the MΩ range, which reduces the drive currents to negligible magnitudes and inhibits proper switching behavior of the FET.…”

Performance Enhancement of Black Phosphorus Field-Effect Transistors by Chemical Doping

“…The presence of a sizable bandgap along with high carrier mobility makes BP a competitive material for future electrical applications [4]- [7]. To date, experimental demonstrations of few-layer BP FETs have been achieved by several groups [8]- [10], and sustain good electrical performance for weeks or months with different passivations techniques [11]- [13], functioning even at radio frequencies [14], [15]. In addition, BP devices are also suitable for optoelectronic applications [16]- [20].…”