Deuterium incorporation in acceptor doped epitaxial layers of 6H-SiC

Deuterium is introduced in boron doped epitaxial layers of 6H-SiC by implantation of 30 keV H-2(+) ions in order to form a diffusion source. The samples were subsequently annealed in vacuum at 700 degrees C/16h, 800 degrees C/4h and 900 degrees C/4h. Using depth profiling by secondary ion mass spectrometry (SIMS), the distributions of deuterium at different levels of boron doping are studied. The deuterium concentration correlates with the boron concentration and at a level of similar to 10(18) cm(-3) a ratio H-2/B-11 larger than 0.5 is obtained. From capacitance-voltage (CV) measurements a decrease in the electrical carrier concentration by 50% is revealed after deuterium diffusion at 800 degrees C/4h. At 900 degrees C passivation of the boron accepters ceases but the H-2 atoms are still confined to the boron-doped regions and display no long range migration.