Migliore Francesca, Cannas Marco, Gelardi Franco Mario, Pasquali Filippo, Brischetto Andrea, Vecchio Daniele, Pirnaci Massimo Davide, Agnello Simonpietro
Department of Physics and Chemistry Emilio Segrè, University of Palermo, Via Archirafi 36, 90123 Palermo, Italy.
STMicroelectronics, Stradale Primosole, 95121 Catania, Italy.
Materials (Basel). 2024 Nov 25;17(23):5761. doi: 10.3390/ma17235761.
Silicon carbide is a wide-bandgap semiconductor useful in a new class of power devices in the emerging area of high-temperature and high-voltage electronics. The diffusion of SiC devices is strictly related to the growth of high-quality substrates and epitaxial layers involving high-temperature treatment processing. In this work, we studied the thermal stability of substrates of 4H-SiC in an inert atmosphere in the range 1600-2000 °C. Micro-Raman spectroscopy characterization revealed that the thermal treatments induced inhomogeneity in the wafer surface related to a graphitization process starting from 1650 °C. It was also found that the graphitization influences the epitaxial layer successively grown on the wafer substrate, and in particular, by time-resolved photoluminescence spectroscopy it was found that graphitization-induced defectiveness is responsible for the reduction of the carrier recombination lifetime.
碳化硅是一种宽带隙半导体，在高温和高压电子学这一新兴领域的新型功率器件中很有用。碳化硅器件的扩散与高质量衬底和外延层的生长密切相关，这涉及高温处理工艺。在这项工作中，我们研究了4H-SiC衬底在1600-2000°C惰性气氛中的热稳定性。显微拉曼光谱表征表明，从1650°C开始的石墨化过程导致热处理在晶圆表面产生不均匀性。还发现石墨化会影响随后在晶圆衬底上生长的外延层，特别是通过时间分辨光致发光光谱发现，石墨化引起的缺陷是载流子复合寿命降低的原因。
