Linear energy transfer dependence of single event gate rupture in SiC MOS capacitors

Deki, Manato; Makino, Takahiro; Iwamoto, Naoya; Onoda, Shinobu; Kojima, Kazutoshi*; Tomita, Takuro*; Matsuo, Shigeki*; Hashimoto, Shuichi*; Oshima, Takeshi

Single Event Gate Rupture (SEGR) in SiC MOS capacitors fabricated on 4H-SiC was studied. In particular, we evaluate the linear energy transfer (LET) dependence of critical electric field (Ecr) at which SEGR occurs in SiC MOS capacitors. The MOS capacitors were irradiated with either oxygen (O) or nickel (Ni) ions at 18 MeV. The leakage current through the gate oxide of the MOS capacitors was monitored under applied biases up to 100 V. The LET of O and Ni ions at 18 MeV are 7.02 and 23.8 MeV cm/mg, respectively. For No significant difference in Ecr between 18 MeV-O irradiated and non-irradiated (LET=0) samples was observed. This result suggests that charge density generated in SiC by 18 MeV-O was not enough to induce SEGR. On the other hand, Ecr for samples irradiated with 18 MeV-Ni was lower than that for a sample irradiated with 18 MeV-O. We confirmed that Ecr decreased with increasing LET of incident ions, and the relationship is similar to that of silicon MOS capacitors.