SrSnO₃ Field-Effect Transistors With Recessed Gate Electrodes

Doping the Undopable: Hybrid Molecular Beam Epitaxy Growth, n-Type Doping, and Field-Effect Transistor Using CaSnO3

“…Finally, the temperature-dependent transfer characteristics are shown in Figure g, where I D was found to decrease by roughly 1/2 going from 300K to 77 K. Since the film itself displays metallic behavior, as shown in the Hall measurements taken before fabrication in Figure S11, this temperature dependence must arise from the contacts. This, in turn, suggests that the contacts still have a thermionic component and that further improvement could be achieved by using a recessed gate design with higher doping in the contact regions, as previously demonstrated for SrSnO 3 MESFETs …”

“…This, in turn, suggests that the contacts still have a thermionic component and that further improvement could be achieved by using a recessed gate design with higher doping in the contact regions, as previously demonstrated for SrSnO 3 MESFETs. 35 Given the potential of CaSnO 3 for high-power devices due to its large band gap, we also performed high-voltage measurements on these devices. For these measurements, we chose a device with L DS = 15 μm and L G = 3 μm and gate-todrain spacing, L GD , of 9 μm.…”

“…The low drive current is a result of (1) the relatively low channel doping, which limits the intrinsic current carrying capacity of the devices, and (2) the high contact resistance (∼500 Ω-mm), which is also a result of the low doping. Much higher doping is needed to create tunneling contacts, and the use of a thinner channel region and a recessed-gate geometry 35 could allow devices to achieve higher drive current and transconductance. An estimate of the fieldeffect mobility in our devices was obtained from the intrinsic g m (0.22 mS/mm) and the device capacitance which yielded an apparent field-effect mobility, μ FE , of 1.2 cm 2 /(V s).…”

Post-annealing optimization of the heteroepitaxial La-doped SrSnO3 integrated on silicon via ALD

“…13,46 For producing high film quality, previous studies on SSO were mostly focused on molecular beam epitaxy (MBE). [46][47][48] However, for the stannate perovskite growth, MBE has shown volatility issues with SnO and Sn sources, and difficulty for the SnO 2 source to achieve stable film stoichiometry. 40 Furthermore, the elevated thermal budget of MBE is incompatible with CMOS back-end-of-line (BEOL) processes, constraining the use of alkaline-earth stannate TOSs.…”

Hysteretic Magnetoresistance in a Non-Magnetic SrSnO3 Film via Thermal Coupling to Dynamic Substrate Behavior

“…This material belongs to a family of nonmagnetic alkaline-earth stannates (ASnO 3 ; A = Ca, Sr or Ba), which have gained significant interest in recent years owing, in large part, to their (ultra)­wide bandgap and high room-temperature electron mobility. , These characteristics of stannates have paved the way for their use in transparent and high-power electronic applications. Motivated by this, significant progress has been made in synthesizing BaSnO 3 (BSO) and SSO films with atomic layer control using a variety of growth methods. − Although there are no studies of transport in bulk SSO single crystals, several exciting developments have occurred in SSO thin films including the demonstration of oxygen vacancy-induced room-temperature ferromagnetism, , high conductivity, a weak localization and Aronov–Altshuler electron–electron interaction, a large phase coherence length, and several field-effect devices − including those operating at GHz frequencies . As we will show, the insulating transport behavior achievable in this material make it a highly sensitive probe for the subtle thermal effects arising from the substrate.…”