Photoemission of 4H-SiC pin-Diodes Epitaxied by the Sublimation Method

Abstract

4H-SiC pin diodes were fabricated on epitaxial layers grown by Sandwich Sublimation Method (SSM). I-V and photoemission measurements were conducted on these devices. These measurements show hot spots responsible for a soft breakdown and evidence triangular shape defects previously observed in 4H-SiC pin diodes made on CVD epitaxial layers. These results agree with the morphology studies which indicate that the SSM-grown layers have a higher number of structural defects than their counterparts.

Drift Phenomena of Forward and Reverse Recovery Characteristics in 0001 4H-SiC p–i–n Diode

“…the basal plane dislocations in the drift layer but also dislocation loops in a basal plane localized near the surface and the mesa wall. 18,19) The dislocation loop density has small dependence on the crystal face as compared with the basal plane dislocation density. 20) In our experiment, V F of p-i-n diode fabricated on the ð000 " 1Þ C-face has smaller change between before and after the stress test as compared with that on the (0001) Si-face.…”

Microwave p-i-n Diodes Fabricated on 4H-SiC Material Grown by Sublimation Epitaxy in Vacuum

“…The thickness and the doping level of the epitaxial layers are reported in table 1. Typical surface morphology results as well as the investigation of material defects by observing, through the substrate, the forward and reverse-bias-induced light emission in the SEV-grown p-i-n diode structures have been reported elsewhere [4].…”

4H-SiC p–i–n diodes grown by sublimation epitaxy in vacuum (SEV) and their application as microwave diodes

“…Photo-emission microscopy, correlated with electrical measurements, is a suitable method for characterizing the quality of p-i-n diode epitaxial structures. Light emission coming from the biased devices was collected through the substrate and focused by a microscope on a CCD camera [20,21]. The hot luminous spots observed under reverse bias (figure 8(a)) are attributed to structural defects mainly threading dislocations.…”

“…Spectral analysis of the images taken at bias higher than 2.5 V, shows that the triangles border parallel to surface steps emit at 450 nm while the rest of the surface emits at 500-600 nm. The origin of these triangular defects are basal plane dislocations serving as nucleation sites for stacking faults which propagate under a high forward current density [21]. Like in the case of CVD-grown layers, dislocations from the substrate propagate though the epitaxial layers and have the same spectral signature, in the 600-900 nm wavelength range.…”