화학공학소재연구정보센터
Materials Science Forum, Vol.338-3, 969-972, 2000
Vacancy-type detects in proton-irradiated 6H-and 4H-SiC: A systematic study with positron annihilation techniques
Annealing of defects in proton irradiated bulk 6H- and 4H-SiC has been investigated by positron lifetime spectroscopy and Doppler-broadening measurements. The experiments were performed on N-doped (n-type) or Al-doped (p-type) crystals with carrier concentrations N-D - N-A = 2.0x10(17) - 3.2x10(18) cm(-3) and N-A - N-D = 3.8x10(18) - 6.2x10(18) cm(-3), respectively, and in semiinsulating samples. In n-type material the radiation induced defects anneal out in four annealing stages: 150 degreesC, 350 degreesC, 750 degreesC and higher than 1000 degreesC. The magnitude of the respective annealing stages depends on the proton fluence. In p-type material the increase of the positron parameters after proton irradiation is smaller and a different annealing behaviour is observed after the first annealing stage at about 150 degreesC. The semi-insulating samples do not show the annealing stage at 1000 degreesC.