In this study, we utilize electrically detected magnetic resonance (EDMR) techniques and electrical measurements to study defects in SiC based metal oxide semiconductor field effect transistors (MOSFETs). We compare results on a series of SiC MOSFETs prepared with significantly different processing parameters. The EDMR is detected through spin dependent recombination (SDR) in most cases. However, in some devices at a fairly high negative bias, the EDMR likely also involves spin dependent trap-assisted tunneling (SDT) between defects on both sides of the SiC/SiO2 interface. At least three different defects have been detected in the magnetic resonance measurements. The defects observed include two at the SiC/SiO2 interface or on the SiC side of the SiC/SiO2 interface: one is very likely a vacancy center with a distribution which extends into the bulk of the SiC and the other is likely a “dangling bond” defect. A third defect, located on the SiO2 side of the SiC/SiO2 interface, has a spectrum very similar to that previously reported for an oxygen deficient silicon coupled to a hydrogen atom. In nearly all cases, we observe a strong dominating single line EDMR spectrum with an isotropic g≈2.0027. In some samples, this strong central line is accompanied by two pairs of considerably weaker side peaks which we link to hyperfine interactions with nearby Si and C atoms. The pattern is physically reasonable for a silicon vacancy in SiC. We therefore tentatively assign it to a silicon vacancy or silicon vacancy associated defect in the SiC. In one set of devices with very high interface trap density we observe another dominating spectrum with g∥=2.0026 and g⊥=2.0010 with the symmetry axis coincident with the [0001] and nearly the SiC/SiO2 interface normal. We ascribe this EDMR spectrum to a “dangling bond” defect. A third EDMR spectrum shows up in some devices at a fairly large negative gate bias. The phase of this spectrum is quite consistently opposite to that of the SDR detected EDMR at other biases. Part of this inverted phase spectrum involves two narrow lines which are separated by ≈10.5 G. Since the center responsible for this spectrum is almost certainly in the SiO2, it is likely due to the so called 10.4 G doublet center, an unpaired electron residing on an oxygen deficient silicon atom coupled to a hydrogen in SiO2. The likely presence of one oxygen deficient silicon defect suggests that other oxygen deficient silicon atom defect sites in the oxide may also be important in SiC/SiO2 devices. Oxygen deficient silicon defects in SiO2 are typically called E′ centers. Our results collectively demonstrate considerable complexity in both the chemical composition and physical distribution of performance limiting defects in SiC transistors, with defects observed on both sides of the SiC/SiO2 interface. Our results most strongly indicate that fairly high densities of intrinsic deep-level defects, likely due to a Si vacancy or a closely related defect, extend into the bulk of the SiC in all but one of the devices prepared utilizing a fairly wide range of processing parameters.

The jovian system is of particular interest for studying magnetic induction in icy ocean worlds. Jupiter has a strong magnetic field whose dipole axis is tilted 9.6° with respect to its rotation axis (Acuna & Ness, 1976), while the orbits of the Galilean moons lie very nearly in the equatorial plane of Jupiter. This means that Jupiter's magnetic field varies in time at the orbital positions of the satellites. Also, the outer layers of the

Magnetometers are essential for scientific investigation of planetary bodies and are therefore ubiquitous on missions in space. Fluxgate and optically pumped atomic gas based magnetometers are typically flown because of their proven performance, reliability, and ability to adhere to the strict requirements associated with space missions. However, their complexity, size, and cost prevent their applicability in smaller missions involving cubesats. Conventional solid-state based magnetometers pose a viable solution, though many are prone to radiation damage and plagued with temperature instabilities. In this work, we report on the development of a new self-calibrating, solid-state based magnetometer which measures magnetic field induced changes in current within a SiC pn junction caused by the interaction of external magnetic fields with the atomic scale defects intrinsic to the semiconductor. Unlike heritage designs, the magnetometer does not require inductive sensing elements, high frequency radio, and/or optical circuitry and can be made significantly more compact and lightweight, thus enabling missions leveraging swarms of cubesats capable of science returns not possible with a single large-scale satellite. Additionally, the robustness of the SiC semiconductor allows for operation in extreme conditions such as the hot Venusian surface and the high radiation environment of the Jovian system.

A spin dependent recombination (SDR) spectrum observed in a wide range of SiC metal oxide semiconducting field effect transistors (MOSFETs) has previously been only tentatively linked to a silicon vacancy or vacancy related defect. By resolving hyperfine interactions in SDR detected spectra with 13C nuclei, we provide an extremely strong argument identifying the SDR spectrum with a silicon vacancy. Since the silicon vacancy spectrum dominates the SDR response in a wide variety of SiC MOSFETs, silicon vacancies are quite important traps in this technology.

Neptune's largest moon Triton (radius 𝐴𝐴 𝐴𝐴𝑇𝑇 = 1, 353 km) is thought to be an erstwhile Kuiper belt object that was captured by the ice giant (Agnor & Hamilton, 2006). Orbiting at a radial distance of 𝐴𝐴 14.4𝑅𝑅𝑁𝑁 (radius of Neptune 𝐴𝐴 𝐴𝐴𝑁𝑁 = 24, 622 km), Triton is always located within Neptune's magnetosphere (Curtis & Ness, 1986;Mejnertsen et al., 2016;Ness et al., 1989;Richardson, 1993). The moon's highly inclined orbit-tilted nearly 𝐴𝐴 157 • with respect to its parent planet's rotational equator-results in a retrograde orbital motion around Neptune. Triton possesses the second-most dense moon atmosphere in the solar system after Titan (Broadfoot et al., 1989;Strobel et al., 1990;Strobel & Zhu, 2017). Mainly comprised of neutral 𝐴𝐴 N2 , its maximum surface number density is on the order of 𝐴𝐴 10 15 cm −3 , with a scale height between 10 and 70 km (Broadfoot et al., 1989). Additionally, trace gases including methane are present, with surface densities below 𝐴𝐴 10 11 cm −3 (e.g., Summers & Strobel, 1991;Trafton, 1984;Krasnopolsky et al., 1992). This neutral envelope is predominantly ionized by a combination of magnetospheric electron impacts and photoionization, resulting in an ionospheric Pedersen conductance that may exceed 𝐴𝐴 10 4 S (Strobel et al., 1990). In addition to this global atmosphere, observations during the Voyager 2 encounter of Neptune in 1989 indicated localized, geyser-like vapor plumes emanating from the surface to an altitude of ∼10 km (Smith et al., 1989). Since the moon's interior is likely differentiated in a hydrosphere and rocky mantle, it is possible that these plumes originate from a global, deep ocean sustained via radiogenic heating and/or tidal forcing (Nimmo & Spencer, 2015).