Characterization of SiO2/4H-SiC Interfaces in 4H-SiC MOSFETs: A Review

This paper gives an overview on some state-of-the-art characterization methods of SiO2/4H-SiC interfaces in metal oxide semiconductor field effect transistors (MOSFETs). In particular, the work compares the benefits and drawbacks of different techniques to assess the physical parameters describing the electronic properties and the current transport at the SiO2/SiC interfaces (interface states, channel mobility, trapping phenomena, etc.). First, the most common electrical characterization techniques of SiO2/SiC interfaces are presented (e.g., capacitance- and current-voltage techniques, transient capacitance, and current measurements). Then, examples of electrical characterizations at the nanoscale (by scanning probe microscopy techniques) are given, to get insights on the homogeneity of the SiO2/SiC interface and the local interfacial doping effects occurring upon annealing. The trapping effects occurring in SiO2/4H-SiC MOS systems are elucidated using advanced capacitance and current measurements as a function of time. In particular, these measurements give information on the density (~1011 cm−2) of near interface oxide traps (NIOTs) present inside the SiO2 layer and their position with respect to the interface with SiC (at about 1–2 nm). Finally, it will be shown that a comparison of the electrical data with advanced structural and chemical characterization methods makes it possible to ascribe the NIOTs to the presence of a sub-stoichiometric SiOx layer at the interface.

Quantification of ion migration in CH3NH3PbI3 perovskite solar cells by transient capacitance measurements

We quantify activation energy, concentration, and diffusion coefficient of mobile ions in MAPbI3 perovskite solar cells using transient ion-drift measurements.

Oxide Traps Probed by Transient Capacitance Measurements on Lateral SiO2/4H-SiC MOSFETs

In this paper, near interface traps (NITs) in lateral 4H-SiC MOSFETs were investigated employing temperature dependent transient gate capacitance measurements (C-t). TheC-tmeasurements as a function of temperature indicated that the effective NITs discharge time is temperature independent and electrons from NITs are emitted toward the semiconductor via-tunnelling and/or trap-to-trap tunnelling. The NITs discharge time was modelled taking into account also the interface state density in a distributed circuit and it allowed to locate traps within a distance of about 1.3nm from the SiO2/4H-SiC interface.