The diffusion of deuterium (H-2) in p-type 4H-silicon carbide (SiC) has been studied in detail by secondary ion mass spectrometry. An effective capture radius for the formation of H-2-B complexes at 460 degreesC is determined to R-HB = (21 +/- 4) A. This value is in good agreement with that expected for a coulomb force-assisted trapping mechanism. At higher temperatures, the H-2 diffusion follows Fick's law with a constant effective diffusivity from which the complex dissociation frequencies nu (HB) are determined. The frequencies exhibit an Arrhenius temperature dependence over the three orders of magnitude covered by the extracted nu (HB). The complex dissociation energy is determined to E-d(HB) = (2.51 +/- 0.04) eV which is 0.9 eV larger than the corresponding value for the H-2-Al complex, suggesting that the atomic configurations for the two complexes are significantly different. The extracted dissociation attempt frequency, nu (HB)(0) = (1.2 +/- 0.7) x 10(13) s(-1) is very close to the characteristic oscillation frequency of the SiC lattice, nu (SiC)(lattice) = 1.6 x 10(13) s(-1). In addition, H-2 diffusion in an epitaxial AI multilayer structure demonstrates the influence of internal electric fields on the H-2 diffusion in p-type SiC.