In this paper, we study the electrochemical anodization of n-type heavily doped 4H-SiC wafers in HF based electrolytes without any UV light assistance. We present, in particular, the differences observed when varying the process conditions such as the HF concentration, the type of additive and the applied current regime. The use of a solvent such as acetic acid seems to be more suitable to produce homogeneous morphologies compared with Cetyltrimethylammonium chloride (CTAC), Ammonium dodecylsulfate (ADS), Triton X-100 surfactants. In addition, the use of pulsed current regimes improves the global homogeneity of the porous layers. Nevertheless, for some unexplained reasons, at specific concentrations of 15 and 50%, this homogeneity cannot be ensured and the observed morphology mixes mesopores and macropores with random orientations.

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Due to their wide band gaps, III-N materials can exhibit behaviors ranging from the semiconductor class to the dielectric class. Through an analogy between a Metal/AlGaN/AlN/GaN diode and a MOS contact, we make use of this dual nature and show a direct path to capture the energy band diagram of the nitride system. We then apply transparency calculations to describe the forward conduction regime of a III-N heterojunction diode and demonstrate it realizes a tunnel diode, in contrast to its regular Schottky Barrier Diode designation. Thermionic emission is ruled out and instead, a coherent electron tunneling scenario allows to account for transport at room temperature and higher.