Electronic and Optical Properties of Threading Dislocations in <i>n</i>-Type 4H-SiC

Luo, Hao; Li, Jiajun; Yang, Guang; Zhu, Ruzhong; Zhang, Yiqiang; Wang, Rong; Yang, Deren; Pi, Xiaodong

doi:10.1021/acsaelm.1c01330

Cited by 17 publications

(16 citation statements)

References 38 publications

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“…As shown in Figure (e), the band-edge emission at 390 nm and the broad-band emission ranging from 450 to 650 nm are found in the perfect n -type 4H-SiC [(100)] sample and the SF region. Similar to previous research, the broad-band emission is attributed to oxygen complexes in 4H-SiC. − In addition, the emission band centered at 426 nm appears on the PL spectra of the SF region, which is the same as the band-edge emission of 6H-SiC. , The intensity mapping of the PL peak located at 426 nm is carried out across several horizontal-ridge SFs. As shown in Figure (f), all SFs have a higher PL intensity at 426 nm, indicating that the SFs revealed by the PCE in this work have the Si–C stacking sequence of (3,3).…”

Section: Resultssupporting

confidence: 77%

Role of the Growth Facet on the Generation and Expansion of Stacking Faults in PVT-Grown n-Type 4H-SiC Single-Crystal Boules

et al. 2023

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The generation and expansion of stacking faults (SFs) during the physical-vapor-transport (PVT) growth of n-type 4H-SiC single-crystal boules are investigated by combining photochemical etching, transmission electron microscopy, microphotoluminescence, and micro-Raman investigations. SFs with the Si−C bilayer stacking sequence of (3,3) in Zhdanov's notation are found near the seed crystal of the n-type 4H-SiC. Interestingly, we find that the facet region of the n-type 4H-SiC single-crystal boule is free of SFs (3,3). Most of the SFs (3,3) are constrained in the nonfaceted region of n-type 4H-SiC. Micro-Raman analysis indicates that the shear stress exerted in the nonfacet region gives rise to the formation and expansion of SFs (3,3), which releases the shear stress during the PVT growth of n-type 4H-SiC single-crystal boules. Due to the differences of nitrogen concentrations and growth velocities between the facet and nonfacet regions of the n-type 4H-SiC single-crystal boule, high compressive stress appears in the interface of the facet and nonfacet regions, which impedes the expansion of SFs (3,3). Furthermore, the shear stress in the facet region of a PVT-grown n-type 4H-SiC single-crystal boule is nearly zero, which eliminates the generation and expansion of SFs in the 4H-SiC single-crystal boule.

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Section: Resultssupporting

confidence: 77%

Role of the Growth Facet on the Generation and Expansion of Stacking Faults in PVT-Grown n-Type 4H-SiC Single-Crystal Boules

et al. 2023

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“…The absence or presence of the mixed component can be obtained by evaluating the shape and luminescence properties of a TSD etch pit. 17,32) Figure 4(a) shows the SEM images of the KOH-etched TSD-A, B, C, and D in the SiC sample. The strained atoms surrounding the dislocations are vulnerable to the attack of OH − .…”

Section: Resultsmentioning

confidence: 99%

“…It has been reported that the shapes and luminescence spectra of alkali-etched TSDs varied with the absence or presence of a mixed component of the Burgers vector. 17) Using the results obtained from 3D μ-XRT, SEM, and CL, the relationship between the structure and component in TSD was discussed.…”

Section: Introductionmentioning

confidence: 99%

3D structure of threading screw dislocation at a deep location in 4H-SiC using 3D micro-X-ray topography

Ishiji,

Yoneyama,

Inaba

et al. 2024

Jpn. J. Appl. Phys.

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We used three-dimensional micro-X-ray topography (3D μ-XRT) to construct a three-dimensional structure of the threading screw dislocations (TSDs) in 4H-SiC. The 00012 diffraction condition which can observe the strain field at a deep location in the sample was employed in the 3D μ-XRT geometry. The dislocation core-lines of TSDs propagating from the surface to the interior of the sample were successfully captured spatially, and TSDs parallel to and inclined from the <0001> axis were both confirmed. Either the component <1(−)1(−)20> or <1(−)100> of the Burgers vector is considered to be mixed in the inclined TSD. To verify this suggestion, scanning electron microscopy (SEM) and cathodoluminescence (CL) spectroscopy were performed on the molten-alkali-etched TSDs. Both the SEM shapes and CL intensities of the TSD etch pits with inclination showed the features of the mixed component, supporting the correlation between the inclination and mixed component in TSD.

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“…According to the Burgers vectors and dislocation-line directions, dislocations in 4H-SiC can be classified as threading edge dislocations (TEDs), threading edge dislocations (TSDs), threading edge dislocations (TMDs), and basal plane dislocations (BPDs) (Nakamura et al, 2007;Li et al, 2022;Luo et al, 2022). It has been found that all the dislocations increase the leakage current of 4H-SiC power devices, and the effect of TSDs is more prominent than those of TEDs (Wahab et al, 2000;Berechman et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Dislocation-related leakage-current paths of 4H silicon carbide

et al. 2023

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Improving the quality of 4H silicon carbide (4H-SiC) epitaxial layers to reduce the leakage current of 4H-SiC based high-power devices is a long-standing issue in the development of 4H-SiC homoepitaxy. In this work, we compare the effect of different type of dislocations, and discriminate the effect of dislocation lines and dislocation-related pits on the leakage current of 4H-SiC by combining molten-KOH etching and the tunneling atomic force microscopy (TUNA) measurements. It is found that both the dislocation lines of threading dislocations (TDs) and the TD-related pits increase the reverse leakage current of 4H-SiC. The dislocation lines of TDs exert more significant effect on the reverse leakage current of 4H-SiC, which gives rise to the nonuniform distribution of reverse leakage current throughout the TD-related pits. Due to the different Burgers vectors of TDs, the effect of TDs on the reverse leakage current of 4H-SiC increases in the order to threading edge dislocation (TED), threading screw dislocation (TSD) and threading mixed dislocation (TMD). Basal plane dislocations (BPDs) are also found to slightly increase the reverse leakage current, with the leakage current mainly concentrated at the core of the BPD. Compared to the effect of TDs, the effect of BPDs on the reverse leakage current of 4H-SiC is negligible. Our work indicates that reducing the density of TDs, especially TMDs and TSDs, is key to improve the quality of 4H-SiC epitaxial layers and reduce the reverse leakage current of 4H-SiC based high -power devices.

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Electronic and Optical Properties of Threading Dislocations in n-Type 4H-SiC

Cited by 17 publications

References 38 publications

Role of the Growth Facet on the Generation and Expansion of Stacking Faults in PVT-Grown n-Type 4H-SiC Single-Crystal Boules

Role of the Growth Facet on the Generation and Expansion of Stacking Faults in PVT-Grown n-Type 4H-SiC Single-Crystal Boules

3D structure of threading screw dislocation at a deep location in 4H-SiC using 3D micro-X-ray topography

Dislocation-related leakage-current paths of 4H silicon carbide

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