Synchrotron X-Ray Topography Studies of the Propagation and Post-Growth Mutual Interaction of Threading Growth Dislocations with C-Component of Burgers Vector in PVT-Grown 4H-SiC

We performed a plan-view and cross-sectional photoluminescence (PL) imaging and a spectral analysis of threading dislocations in 4H-SiC epilayers in the near-infrared region. The bright PL spots of threading screw dislocations (TSDs) and threading edge dislocations (TEDs) observed in the plan-view PL imaging are compared with the grazing incidence synchrotron X-ray topography contrast, and precise discrimination of threading dislocations using the PL technique and the direct acquisition of Burgers vector directions of TEDs are demonstrated. The inclination angles of TSDs and TEDs across a thick epilayer are revealed by the cross-sectional PL imaging, and the variations in the plan-view PL appearances of the threading dislocations are confirmed to originate from the line directions of such dislocations.

Section: Resultsmentioning

confidence: 97%

Plan-View and Cross-Sectional Photoluminescence Imaging Analyses of Threading Dislocations in 4H-SiC Epilayers

Nagano

Kamata

Tsuchida

2013

“…Similar wavy TSDs in PVT-grown 4H-SiC crystals were reported by Wu et al using synchrotron X-ray topography. 25) They observed TSDs showing curved, slightly wavy morphologies in the crystals, and suggested that they were helical TSDs resulting from the interaction of a nonequilibrium concentration of vacancies with TSDs. They also found that the attractive interaction between closely located two helical TSDs with opposite signs of Burgers vectors resulted in partial annihilation of the dislocation lines.…”

Section: Propagation Behaviors Of Pure and Mixedmentioning

confidence: 99%

Populations and propagation behaviors of pure and mixed threading screw dislocations in physical vapor transport grown 4H-SiC crystals investigated using X-ray topography

Shinagawa

Izawa

Manabe

et al. 2020

The populations and propagation behaviors of pure and mixed threading screw dislocations (TSDs) in physical vapor transport (PVT) grown 4H-SiC crystals were investigated using X-ray topography. The X-ray topography studies revealed that mixed TSDs, which have a Burgers vector component within the basal plane in addition to the c-component, were dominant in PVT-grown 4H-SiC crystals, even though they have a higher energy contained in the elastic field around them compared to pure TSDs. The studies also revealed that mixed TSDs tended to propagate in a specific direction inclined from the c-axis, whereas pure TSDs were often converted into helical dislocations during the PVT growth. Based on these results, we discussed the nature and propagation behavior of pure and mixed TSDs in PVT-grown 4H-SiC crystals and suggested an importance of the interaction between TSDs and point defects during PVT growth of 4H-SiC.

“…4) However, 4H-SiC epitaxial layers (epilayers) still contain many dislocations such as threading screw dislocations (TSDs), threading edge dislocations (TEDs) and basal plane dislocations (BPDs), 5) which can degrade the performance of the devices. 6,7) To improve device performance and reliability, it is important to distinguish dislocation types [8][9][10][11][12][13][14][15][16][17][18][19][20] and investigate their electrical effects on devices. [21][22][23] The KOH etching method is widely used to determine the locations and kinds of dislocations in 4H-SiC epilayers.…”

Section: Hmentioning

confidence: 99%

X-ray topographical analysis of 4H-SiC epitaxial layers using a forward-transmitted beam under a multiple-beam diffraction condition

Kamata

Tsusaka

Tanuma

et al. 2018

Multiple-beam diffraction X-ray topography was used to determine the Burgers vector b of threading edge dislocations (TEDs) and basal plane dislocations (BPDs) in 4H-SiC epitaxial layers. In hexagonal crystals, the technique simultaneously yields five different diffractions corresponding to different diffraction vectors g. Hence, this method enables us to determine the components of b using the g · b = 0 rule without widely changing the diffraction geometry. The b vectors of TEDs and BPDs were successfully determined by the method. These results were then confirmed by ordinary grazing-incidence X-ray topography in order to verify the validity of this technique.