Large area, ultra-high voltage 4H-SiC p-i-n rectifiers

Abstract

This paper reports the design, fabrication and high temperature characteristics of 1 mm 2 , 4 mm 2 and 9 mm 2 4H-SiC p-in rectifiers with 6 kV, 5 kV, and 10 kV blocking voltage, respectively. These results were obtained from two lots in an effort to increase the total power levels on such rectifiers. An innovative design utilizing a highly doped p-type epitaxial Anode layer and junction termination extension (JTE) were used in order to realize good on-state as well as stable blocking characteristics. For the 1 mm 2 and 4 mm 2 rectifier, a forward voltage drop of less than 5 V was observed at 500 A/cm 2 and the peak reverse recovery current shows a modest 50% increase in the 25 C to 225 C temperature range. On the 10 kV, 9 mm 2 rectifier, a forward voltage drop of less than 4.8 V was observed at 100 A/cm 2 in the entire 25 C to 200 C temperature range. For this device, the reverse recovery characteristics show a modest 110% increase in the peak reverse recovery current from 25 C to 200 C. A dramatically low rr of 3.8 C was obtained at a forward current density of 220 A/cm 2 at 200 C for this ultra high voltage rectifier. These devices show that more than three orders of magnitude reduction in reverse recovery charge is obtained in 4H-SiC rectifiers as compared to comparable Si rectifiers.

Promise and Challenges of High-Voltage SiC Bipolar Power Devices

“…As a typical example, the forward characteristics of SiC pin diodes having an i-layer thickness of 200 µm (28 kV class) are presented in Figure 3, where the carrier lifetime in the i-layer was changed from 1 µs to 100 µs (an analytical expression for the characteristics of a pin diode and brief discussion are given in Note S1). As expected, the characteristics are remarkably improved by increasing the carrier lifetime, which is consistent with the studies on lower-voltage SiC pin diodes reported in literature [33,34]. Note that the carrier lifetimes longer than 10 µs do not contribute very much to reduction of the forward voltage drop.…”

The fabrication and research Of 4H-Sic Schottky metal-semiconductor-metal ultraviolet photodetectors

“…As a wide bandgap semiconductor material, silicon carbide(SiC) is an ideal materials for high frequency, high power and anti-radiation devices which can operate in high temperature and hostile environments [I , 2,3]. SiC is also an attractive wide bandgap material for ultraviolet(UV) detection owing to its wide bandgaps, material maturity and stability [4,5,6].…”

Physical modelling of large area 4H-SiC PiN diodes

“…PiN diodes fabricated in SiC offer high current density operation with on-state voltage drop values comparable to stacked Si devices, reduced switching losses due to thinner epitaxial layers and high temperature operation [2], [4]. Si PiN diodes suffer from slow switching speeds beyond 3 kV due to thicker base regions and subsequent higher levels of stored charge.…”