  We report on boron-related defects in the low-doped n-type (nitrogen-doped)
4H-SiC semitransparent Schottky barrier diodes (SBDs) studied by minority
carrier transient spectroscopy (MCTS). An unknown concentration of boron was
introduced during chemical vapor deposition (CVD) crystal growth. Boron
incorporation was found to lead to the appearance of at least two boron-related
deep-level defects, namely, shallow (B) and deep boron (D-center), with
concentrations as high as 2 x 1015 cm-3. Even though the boron concentration
exceeded the nitrogen doping concentration by almost an order of magnitude, the
steady-state electrical characteristics of the n-type 4H-SiC SBDs did not
deteriorate.
