Investigation of defect formation in 4H-SiC epitaxial growth by X-ray topography and defect selective etching

Evolution of threading screw dislocation conversion during solution growth of 4H-SiC

“…The knife-shaped contrasts were reported to represent the extended defects on the basal planes which were reported to be composed of 4 Frank partial dislocations each having 1/4[0001] Burgers vector with stacking faults on the (0001) basal plane between them. 7,19,20 In the topography image of the grown crystal taken under the condition #3 [ Fig. 3(c)], the TSDs (A and B ) in seed crystal as well as the extended defects on the basal planes (C and D ) in the grown layer were simultaneously recorded.…”

“…Similar TSD conversion has been reported in the epitaxial growth of SiC by chemical vapor deposition (CVD). 19,20 However, the conversion ratio is as low as 1% in CVD within the growth of about 20 μm. 19 The difference between solution growth and CVD in the conversion ratio would be caused by the difference in the step height.…”

Characterization and Formation Mechanism of Six Pointed Star-Type Stacking Faults in 4H-SiC

“…Although named differently from group to group, three types of stacking faults according to their fault vectors have been reported: Shockley fault with fault vector of a/3 h1 " 100i type, [2][3][4] Frank fault with fault vector of (c/2) [0001] or (c/4) [0001], 5 and those comprising some kind of combination of the previous two. [6][7][8][9][10] Among these faults, Shockley faults have been shown to be associated with the degradation of power devices, as the expansion of such faults in the junction area can impede current flow and, as a result, increase the on-state resistance. 3 In the epilayer, the morphology of the Shockley faults responsible for the device degradation is found to have a rhombus shape with the sides along h11 " 20i directions and angles of 60°and 120°, bounded by 30°partial dislocation loops.…”

Micropipe Reactions in Bulk SiC Growth

“…Such low defect densities are very suitable for x-ray imaging techniques, whose development is pulled by the advent of synchrotron radiation (SR) sources. The combination of synchrotron x-ray topography and optical microscopy succeeded in shedding light on the elucidation of the origin and transformation of dislocations and stacking faults (Tsuchida et al, 2007). The highly coherent beams allowed to analyze dislocation types and structures (Nakamura et al, 2007;Wierzchowski et al, 2007), the Burgers vectors senses and magnitudes (Chen et al, 2008;Nakamura et al, 2008), and the propagation and distribution of threading dislocations (Kamata et al, 2009) …”