Critical issues for interfaces to p-type SiC and GaN in power devices

Quantified hole concentration in AlGaN nanowires for high-performance ultraviolet emitters

“…The lattice and thermal mismatches induce a high dislocation density in AlGaN materials. 3 Additionally, the formation of ohmic contacts in p-type materials is problematic, and the current injection efficiency of UV LEDs is limited due to the high ionization energy of the Mg acceptors, low hole concentration of AlGaN, and difficulty in obtaining metals with low Schottky barriers; [4][5][6] the light extraction efficiency is also limited by the absorption of the p-GaN contact layer used in the structure. 7 The GaN : Mg p-type contact layer when replaced with UVtransparent AlGaN : Mg resulted in an increase in the operating voltage due to the low hole concentration.…”

Atomic scale characterization of SiO2/4H-SiC interfaces in MOSFETs devices

“…for the Si/SiO 2 interface [12]. This roughness at the interface could explain the drastic fall of mobility in the SiC substrate of these MOSFETs compared to the SiC intrinsic bulk mobility [9]. Concerning the p-impl sample, the situation is somehow different as a local oxygen-rich inclusion is evidenced locally in the SiC region as shown in the APT reconstructions (Fig.…”

“…On the other hand, these compositional variations were not observed in later works. In fact, more recent works report that the low mobility is related to the roughness at the interface [8,9]. Note that the SiC/SiO 2 fabrication methods (substrate, post-implantation annealing, oxide growth method, post-annealing ambient) vary in all these studies.…”

Parametric investigation of the formation of epitaxial Ti3SiC2 on 4H-SiC from Al-Ti annealing

“…Epitaxial growth of Ti 3 SiC 2 on 4H-SiC, on-axis and misoriented, by annealing of Al-Ti layered structures was already reported [24][25][26][27][28][29]. However, the chemical paths leading to the formation of single phase were not well understood and many questions remain still unanswered.…”