The photoelastic constant and internal stress around micropipe defects of 6H-SiC single crystal

Scanning electron and polarization microscopy study of the variability and character of hollow macro-defects in silicon carbide wafers

“…As discussed in detail by Kato et al [32], pipes are clearly visible under the light microscope in crossed pole conditions. A unique interference pattern is created by the distribution of internal stresses ( Figure 6).…”

“…88, No. 11, 11 April 2008, would be seen on the (0001)-face of silicon carbide, where the c-and optical axis converge [32].…”

Critical assessment of birefringence imaging of dislocations in 6H silicon carbide

“…In this paper we used the best estimated value which we already determined in our previous publication Fig. 3 [11], which is somewhat higher than the value reported in the only accessible reference where a isotropic piezo-optic coefficient was experimentally assessed [20].…”

“…They thus have to routinely identify and count linear defects in SiC wafers and crystals, a task which can be conveniently achieved through the use of X-ray topography [5], transmission electron microscopy (TEM) [6] or KOH etching [7]. Birefringence microscopy is an additional, nondestructive technique which was proposed by Kato et al [8] and then by Ma et al in the case of SiC [9,10], and subsequently developed by others (see, e.g., [11,12] as well as the Refs. collected in [11]).…”

Residual stress estimation in SiC wafer using IR polariscope

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Relation between optical retardation and transmitted light intensityThe light intensity, I, that comes through the analyzer can be expressed as a Fourier's expansion as follows:Silicon carbide (SiC) single crystals have got into the spotlight as a material for power devices [1]. For quality control of SiC wafers, it is important that the estimation of the optical retardation in the wafers corresponds to the residual stress.

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