Reduction in majority-carrier concentration in N-doped or Al-doped 4H-SiC epilayer by electron irradiation
窒素もしくはアルミニウムをドープした4H-SiCエピタキシャル層の電子線照射による少数キャリア密度減少
松浦 秀治*; 柳澤 英樹*; 西野 公三*; 野尻 琢慎*; 小野田 忍; 大島 武
Matsuura, Hideharu*; Yanagisawa, Hideki*; Nishino, Kozo*; Nojiri, Takunori*; Onoda, Shinobu; Oshima, Takeshi
Change of temperature dependence of hole concentration (p(T)) in lightly Aluminium (Al)-doped 4H-SiC (Silicon Carbide) epilayers by 100 or 150 keV electron irradiation was investigated. Moreover, the decrease in the electron concentration (n(T)) in lightly Nitrogen(N)-doped n-type 4H-SiC epilayers by 200 keV electron irradiation was investigated. In the lightly Al-doped 4H-SiC, p(T) was unchanged by 100 keV electron irradiation at fluences up to 7
10
cm
. However, 150 keV electron irradiation, the reduction of p(T) was observed. This suggests that the 150 keV electron irradiation can displace substitutional carbon (C) atoms in SiC. In the lightly N-doped 4H-SiC, n(T) over the temperature range of the measurement was reduced by 200 keV electrons. This result is quite different from that in the lightly Al-doped 4H-SiC, because p(T) in Al-doped 4H-SiC was reduced only at low temperatures by 200 keV electrons.