Uniform Luminescence at Breakdown in 4H-SiC 4°-Off (0001) p–n Diodes Terminated With an Asymmetrically Spaced Floating-Field Ring

Abstract

Conventional floating-field rings, which are used to reduce the peak electric field at the periphery of power devices, cause nonuniform avalanche multiplication when applied to planar junctions formed on 4H-SiC substrates misoriented from (0001) toward [1120]. Accordingly, a novel asymmetrically spaced floating-field ring (AS-FFR) was applied to 4H-SiC 4 • -off (0001) p-n diodes and found to be effective against such nonuniform avalanche multiplication; that is, luminescence at breakdown was nearly uniform when the spacing between the edge of the anode and the inner edge of the AS-FFR was 2.0 μm in the [1 120] direction and 1.5 μm in the [1120] direction. This result should contribute to exploring the possibility of 4H-SiC power devices with higher avalanche ruggedness.INDEX TERMS Aluminum, ion implantation, power semiconductor devices, silicon compounds.

High-stability 4H-SiC avalanche photodiodes for UV detection at high temperatures

“…Figures 4(a) and 4(b) provide the junction temperature mapping of 4H-SiC APD with different maximum junction temperature of 145°C and 270°C, respectively. It should be noted that the distribution of junction temperature is nonuniform for 4H-SiC APDs, which can be explained by the asymmetric carrier lateral drift in the offorientated 4H-SiC [7,[22][23][24][25] . The results demonstrate that the fabricated 4H-SiC APD can bear a junction temperature of ∼270°C [see Fig.…”

Analyzing charge distribution in the termination area of 4H-SiC diodes by measuring depletion-layer capacitance

“…13,14) Since V BD is typically determined by the termination structure, many termination structures for SiC power devices have been investigated. [15][16][17][18][19][20][21][22][23][24][25][26][27] However, whether the change occurs at the SiO 2 =SiC interface or in the bulk SiC has not been clarified because the change was only indicated by reverse current-reverse voltage (I R -V R ) characteristics. To experimentally determine where the change occurs, the authors previously proposed a novel method: measuring the depletion-layer capacitance in the termination area of SiC PN diodes.…”