Series resistance study of Schottky diodes developed on 4H-SiC wafers using a contact of titanium or molybdenum

We have studied and compared two types of Schottky diodes prepared by the evaporation of molybdenum (Mo) and titanium (Ti) on a 4H-SiC semiconductor. The electrical characteristics of these diodes are analyzed based on the standard thermionic emission model. The main electrical parameters including the series resistance Rs, the ideality factor n and the barrier height ΦB are extracted from current–voltage–temperature (I–V–T) measurements. In the Ti/4H-SiC structure, the series resistance increases from 1.51 mΩ cm2 to 27.68 mΩ cm2 when the temperature is varied from 70 K to 450 K. In contrast, the series resistance does not exceed a 6.17 mΩ cm2 at 450 K in the Mo/4H-SiC Schottky diode. We have decomposed the series resistance into three components. The deduced static and dynamic parameters were used to define an electrical model. The switching behavior of the equivalent circuit indicates a reverse recovery time (Trr) of 1.412 ns for Ti/4H-SiC and 3.27 ns for Mo/4H-SiC.

Figure optionsDownload as PowerPoint slideHighlights
► The series resistance of two types of Schottky diode using 4H-SiC material.
► The effect of temperature on the electrical parameters.
► We proposed an experimental study.
► Electrical model to describe the device in commutation.