Studies of Relaxation Processes and Basal Plane Dislocations in CVD Grown Homoepitaxial Layers of 4H-SiC

Wang, Huanhuan; Wu, Fangzhen; Yang, Y. C.; Guo, Jianqiu; Raghothamachar, Balaji; Dudley, Michael; Zhang, Jie; Chung, Gil Yong; Thomas, Bernd; Sanchez, Edward; Mueller, Stephan G.; Hansen, David M.; Loboda, Mark J.

doi:10.1149/06407.0213ecst

Cited by 2 publications

(1 citation statement)

References 18 publications

(33 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The formation of BPD half-loops extending in the ±[1 100] direction was observed in the vicinity of triangular defects for wafers with growth thicknesses exceeding 50 μm, but not when the thickness of the grown epilayer was below 20 μm. Although the formation of BPDs by triangular defects is still possible in thinner epilayers, as reported in the previous study showing BPDs originating from small triangular defects in 10 μm thick epilayers, 6,28 the results in this study indicate that the BPD formation is clearly dependent on the epilayer thickness. The situation in which BPDs are present in thin (<20 μm) epilayers but they are not detected by synchrotron x-ray topography is also possible.…”

Section: Formation Of Bpd Half-loopssupporting

confidence: 69%

Formation of basal plane dislocations by stress near epilayer/substrate interface of large-diameter SiC wafers with thick epitaxial layers

Fujie,

Shiono,

Murata

et al. 2024

Journal of Applied Physics

View full text Add to dashboard Cite

For large-diameter (150 mm) SiC epitaxial wafers with thick n− epilayers, stress analysis based on the finite element method and defect characterization near the epi/sub interface by synchrotron x-ray topography were performed. Observations on epitaxial wafers with epilayer thicknesses of 10, 20, 50, and 100 μm revealed that basal plane dislocation (BPD) half-loops were formed near triangular defects or from the edge of the wafer at an epilayer thickness of 50 μm and above. Two types of BPD half-loops with different edge components were observed: one with an extra half-plane above the core and present on the substrate side, and the other with a Burgers vector of opposite sign and present in the epilayer and at the epi/sub interface, forming an interfacial dislocation. The signs of these BPDs are consistent with those predicted from the calculation results, which mitigate compressive and tensile stresses in the epilayer and the substrate, respectively. It is considered that a thicker epilayer increases tensile stress in the substrate, which induces the formation of the BPD with an extra half-plane above the core on the substrate side. The distribution of the BPD half-loop width was also analyzed and compared with the calculated shear stress distribution caused by the radial temperature gradient. Calculations considering the local stress near the triangular defect revealed that the tensile stress near the epi/sub interface locally increases, exceeding the critical stress to form BPD, with an extra half-plane above the core for wafers with an epilayer thickness above 50 μm.

show abstract

Section: Formation Of Bpd Half-loopssupporting

confidence: 69%

Formation of basal plane dislocations by stress near epilayer/substrate interface of large-diameter SiC wafers with thick epitaxial layers

Fujie,

Shiono,

Murata

et al. 2024

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

Formation mechanism of horizontal-half-loop arrays and stacking fault expansion behavior in thick SiC epitaxial layers

Mahadik

Stahlbush

Sung

2022

Journal of Applied Physics

View full text Add to dashboard Cite

The formation mechanism of half-loop arrays (HLAs) that form parallel (horizontal) to the step-flow direction in 120 μm thick 4H-silicon carbide (SiC) epitaxial layers was investigated using ultraviolet photoluminescence (UVPL) imaging and x-ray topography (XRT). The horizontal-HLAs are generated by the multiplication and glide of basal plane dislocation (BPD) loops that are created within the epitaxial layer. The BPD loops were initiated after ∼40–50 μm of growth from a small BPD segment, which glides toward the surface as well as the substrate interface. BPD multiplication occurs and several loops are generated. Some of these loops are terminated by the growth front and create HLAs due to the 4° offcut of the wafer. XRT images show that successive BPD loops interact with previously generated HLA segments. Successive loops also interact with the moving growth front and create new HLAs that are spatially displaced from the previous HLA segments. These appear as a string of horizontal-HLAs in the UVPL images. The expansion of stacking faults (SFs) from these horizontal-HLAs was investigated, and we show that they all lie on the same basal plane. The complex defect structure is created in the epitaxial layer from a single BPD loop but extends over a large (∼5 × 0.5 cm2) region of the SiC wafer during epitaxial growth. The high density of HLAs and BPDs would generate several SFs upon device operation leading to severe device degradation.

show abstract

Studies of Relaxation Processes and Basal Plane Dislocations in CVD Grown Homoepitaxial Layers of 4H-SiC

Cited by 2 publications

References 18 publications

Formation of basal plane dislocations by stress near epilayer/substrate interface of large-diameter SiC wafers with thick epitaxial layers

Formation of basal plane dislocations by stress near epilayer/substrate interface of large-diameter SiC wafers with thick epitaxial layers

Formation mechanism of horizontal-half-loop arrays and stacking fault expansion behavior in thick SiC epitaxial layers

Contact Info

Product

Resources

About