Harada Shunta, Mii Toshiki, Sakane Hitoshi, Kato Masashi
Center for Integrated Research of Future Electronics (CIRFE), Institute of Materials and Systems for Sustainability (IMaSS), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan.
Department of Materials Process Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Japan.
Sci Rep. 2022 Aug 15;12(1):13542. doi: 10.1038/s41598-022-17060-y.
SiC bipolar degradation, which is caused by stacking fault expansion from basal plane dislocations in a SiC epitaxial layer or near the interface between the epitaxial layer and the substrate, is one of the critical problems inhibiting widespread usage of high-voltage SiC bipolar devices. In the present study, we investigated the stacking fault expansion behavior under UV illumination in a 4H-SiC epitaxial layer subjected to proton irradiation. X-ray topography observations revealed that proton irradiation suppressed stacking fault expansion. Excess carrier lifetime measurements showed that stacking fault expansion was suppressed in 4H-SiC epitaxial layers with proton irradiation at a fluence of 1 × 10 cm without evident reduction of the excess carrier lifetime. Furthermore, stacking fault expansion was also suppressed even after high-temperature annealing to recover the excess carrier lifetime. These results implied that passivation of dislocation cores by protons hinders recombination-enhanced dislocation glide motion under UV illumination.
SiC双极退化是由SiC外延层中或外延层与衬底界面附近的基面位错导致的层错扩展引起的，是阻碍高压SiC双极器件广泛应用的关键问题之一。在本研究中，我们研究了质子辐照的4H-SiC外延层在紫外光照射下的层错扩展行为。X射线形貌观察表明，质子辐照抑制了层错扩展。过剩载流子寿命测量表明，在通量为1×10¹⁵cm⁻²的质子辐照的4H-SiC外延层中，层错扩展受到抑制，而过剩载流子寿命没有明显降低。此外，即使在高温退火以恢复过剩载流子寿命后，层错扩展也受到抑制。这些结果表明，质子对位错核心的钝化阻碍了紫外光照射下复合增强的位错滑移运动。
