Structure of recombination-induced stacking faults in high-voltage SiC p–n junctions

Abstract

The structure of stacking faults formed in forward-biased 4H- and 6H-SiC p–n− diodes was determined using conventional and high-resolution transmission electron microscopy. Typical fault densities were between 103 and 104 cm−1. All observed faults were isolated single-layer Shockley faults bound by partial dislocations with Burgers vector of a/3〈1–100〉-type.

Quantum well behavior of single stacking fault 3C inclusions in 4H-SiC p-i-n diodes studied by ballistic electron emission microscopy

“…However, the commercialization of 4H-SiC p-i-n diodes ͑bipolar devices͒ is hindered by the formation and propagation of stacking faults ͑SFs͒ in hexagonal basal planes during operation. High-resolution transmission electron microscopy studies showed that the SFs formed this way are all of the "singlelayer" Shockley type produced by the motion of a basalplane partial dislocation 3,4 resulting in a structure that is equivalent to a ϳ0.5-nm-thick 5 planar inclusion with local cubic ͑3C͒ structure embedded in the 4H-SiC host. Based on redshifted luminescence 2,6 and calculations, 5,7 these 3C inclusions were proposed to behave as unique "structure-only" quantum wells ͑QWs͒ due to the ϳ0.9 eV lower conduction band energy of 3C-SiC relative to 4H-SiC.…”

Some Critical Materials and Processing Issues in SiC Power Devices

“…This is a wellunderstood phenomenon in SiC, caused by BPDs. [12][13][14]17 The MOSFET drift layer did not receive a BPD reduction treatment. Hence, the lightly doped n-drift layer of the 4H-SiC DMOSFET had a high density of BPDs.…”

“…12 It was discovered that the basal plane dislocations (BPDs) in the thick epilayers result in the formation of stacking faults (SFs) whenever the PiN diode is forward biased. 13 The size of these SFs depends on the thickness of the epilayer. The SFs represent regions of poor lifetime and therefore, the V F of the diodes increases, presumably due to the poor conductivity modulation in the regions occupied by the SFs.…”

8H-, 10H-, 14H-SiC formation in 6H-3C silicon carbide phase transitions

“…A new type of heterostructure can be created using SiC, namely: heterostructure not between different materials but between different modifications of the same material [17]. Degradation of the electrical characteristics of bipolar SiC devices is explained by the presence of SF in crystal bulk [18,19]. Formation of different polytypes under the same thermodynamic conditions can be understood when using optical spectroscopy analysis [1,20].…”