SDR spectrum of a SiC BJT with magnetic field oriented perpendicular to the crystalline -axis.
SDR spectrum of a SiC BJT with magnetic field oriented parallel to the crystalline -axis.
This figure illustrates a map of values plotted as a function of the angle between the magnetic field and directions in the SiC. The transistor was rotated about three perpendicular axes. The three axes correspond approximately to the , the , and the  directions. Each of the three axes corresponds to one of the maps as indicated in the figure. In the top map, labeled , we plot as a function of the angle between the  direction and the magnetic field. In the middle map, labeled , we plot as a function of the angle between the  direction and the magnetic field. In the bottom map, labeled , we plot as a function of the angle between the direction and the magnetic field. The important conclusion to draw from this figure is that, within our experimental error, ±0.0003, the is independent of magnetic field orientation. It should be emphasized that some weak anisotropy may be present; if so, however, it is below the precision of our measurements.
Derivative of the SDR spectrum shown in Fig. 1.
Top trace is the base-collector junction current vs forward bias voltage. The lower trace is SDR amplitude vs base-collector junction forward bias voltage.
Calculated recombination current (top) vs SDR (bottom) as functions of junction bias.
Ball and stick models of the (a) divacancy and (b) carbon vacancy/antisite defects.
The dotted line illustrates the integral of SDR spectra observed in Fig. 1. The solid line illustrates the expected integrated intensity with hyperfine parameter assumptions: a hyperfine coupling constant of 11 G for the nine nearest neighbor silicons, a coupling of 43 G for the first neighbor silicons, and 34 G for the second neighbor carbons. The numbers in the figure (0.071, 0.064, 0.031,…, correspond to the relative contribution of each Gaussian to the total spectrum.
Comparison of (a) the SDR spectrum obtained for the SiC BJT and (b) and the expected spectrum with the same isotropic hyperfine coupling constants utilized in Fig. 8. (Trace b in this figure is the derivative of the solid line corresponding to the trace in Fig. 8.)
Comparison of the second derivative of (a) the SDR spectrum and (b) the second derivative SDR spectrum based on the same parameters utilized in Figs. 8 and 9. (Trace b in this figure is the derivative of the model calculation trace of 9b.)
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