Reliable single-photon emission is crucial for realizing efficient spin-photon entanglement and scalable quantum information systems. The silicon vacancy (V Si) in 4H-SiC is a promising single-photon emitter exhibiting millisecond spin coherence times, but suffers from low photon counts, and only one charge state retains the desired spin and optical properties. Here, we demonstrate that emission from V Si defect ensembles can be enhanced by an order of magnitude via fabrication of Schottky barrier diodes, and sequentially modulated by almost 50% via application of external bias. Furthermore, we identify charge state transitions of V Si by correlating optical and electrical measurements, and realize selective population of the bright state. Finally, we reveal a pronounced Stark shift of 55 GHz for the V1′ emission line state of V Si at larger electric fields, providing a means to modify the single-photon emission. The approach presented herein paves the way towards obtaining complete control of, and drastically enhanced emission from, V Si defect ensembles in 4H-SiC highly suitable for quantum applications.

The implantation of aluminum into 4H-SiC is studied using secondary ion mass spectrometry. In particular, two-dimensional concentration profiles are obtained, which allow the investigation of lateral straggling and its dependence on the crystallographic orientation. A high dose, medium energy aluminum implantation is studied in great detail. It shows an asymmetric distribution due to the 4°-off axis growth of the epitaxial layer. The lateral straggling is found to be in the range of several micrometers for a concentration of 1×1015 cm−3, which is contrary to the expectation given by most simulation studies. Implantations performed at different orientations support the idea that lateral straggling highly depends on the particular channeling opening.

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Ion implantation is a crucial step in the process of SiC device fabrication. Precise and predictable doping distributions are necessary for reduced cell pitches and integrated circuit development. However, straggling due to ion channeling affects this goal. Even though vertical channeling has been investigated successfully, lateral straggling remains unclear. Therefore, two-dimensional SIMS concentration distributions are used to investigate lateral straggling of Al and P implanted in 4H-SiC. Results, for both Al and P, show that there is a significant influence of the crystal orientation showing that some channels lead to a few micrometers more lateral straggling than others. High implantation doses increase the amount of amorphization, which leads to more dechanneling and, thus, less straggling. Even though elevated implantation temperatures increase lattice vibrations and thus act in favor of dechanneling, the implantation distributions show significant lateral straggling as amorphization is suppressed.

The main scattering mechanisms reducing the channel mobility and thus the typical performance of a SiC power MOSFET are reviewed. It is demonstrated that the Poisson equation within the drift-diffusion model is able to account for the effects of ionized impurity scattering. Furthermore, a correlation between the size of macro-or nanosteps at the SiC/SiO2 interface and the corresponding fitting parameter within the Lombardi surface roughness model is established. By qualitatively reproducing the typical performance of a commercial SiC power MOSFET a baseline for the TCAD modeling of power MOSFETs is provided.

The behavior of silicon carbide power MOSFETs is analyzed using TCAD device simulations with respect to conduction and switching losses. Device designs with varying breakdown voltages are simulated. The contributions to the on-state resistance are shown at room and elevated temperature. Whereas channel and substrate resistance dominate at low breakdown voltages, drift and JFET resistance dominate at high breakdown voltages. With increasing temperature, the channel resistance decreases and thus the drift resistance is the main contributor already at medium breakdown voltages. Manufacturing processes of a device can have a high influence on its losses. Variations in interface mobility, drift doping, and p-body doping can lead to a significant change of on-resistance, internal capacitances, and reverse recovery charge. For higher voltage classes the drift layer properties should be of major interest as it influences on-resistance and reverse recovery charge.

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