A CMOS Compatible Si Template with (111) Facets for Direct Epitaxial Growth of III–V Materials**Supported by the National Natural Science Foundation of China under Grant Nos. 61635011, 61975230, 61804177, 11434041 and 11574356, the National Key Research and Development Program of China (2016YFA0300600 and 2016YFA0301700), and the Key Research Program of Frontier Sciences, CAS (No. QYZDB-SSW-JSC009). Ting Wang is supported by

Abstract

III–V quantum dot (QD) lasers monolithically grown on CMOS-compatible Si substrates are considered as essential components for integrated silicon photonic circuits. However, epitaxial growth of III–V materials on Si substrates encounters three obstacles: mismatch defects, antiphase boundaries (APBs), and thermal cracks. We study the evolution of the structures on U-shaped trench-patterned Si (001) substrates with various trench orientations by homoepitaxy and the subsequent heteroepitaxial growth of GaAs film. The results show that the formation of (111)-faceted hollow structures on patterned Si (001) substrates with trenches oriented along [110] direction can effectively reduce the defect density and thermal stress in the GaAs/Si epilayers. The (111)-faceted silicon hollow structure can act as a promising platform for the direct growth of III–V materials for silicon based optoelectronic applications.