HYDROGEN INCORPORATION IN BORON-DOPED 6H-SIC CVD EPILAYERS PRODUCED USING SITE-COMPETITION EPITAXY

We report on the initial investigations of using site-competition epit axy to control boron incorporation in chemical vapor deposition (CVD) 6H-SiC epilayers. Also reported herein is the detection of hydrogen in boron-doped CVD SiC epilayers and hydrogen-passivation of the boron-a cceptors. Results from low temperature photoluminescence (LTPL) spectr oscopy indicate that the hydrogen content increased as the capacitance -voltage (C-V) measured net hole concentration increased. Secondary io n mass spectrometry (SIMS) analysis revealed that the boron and the hy drogen incorporation both increased as the Si/C ratio was sequentially decreased within the CVD reactor during epilayer growth. Epilayers th at were annealed at 1700 degrees C in argon no longer exhibited hydrog en-related LTPL lines, and subsequent SIMS analysis confirmed the outd iffusion of hydrogen from the boron-doped SiC epilayers. The C-V measu red net hole concentration increased more than threefold as a result o f the 1700 degrees C anneal, which is consistent with hydrogen passiva tion of the boron-acceptors. However, boron related LTPL lines were no t observed before or after the 1700 degrees C anneal.