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 subs...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.展开更多
GaAs/Ge heterostructures have been employed in various semiconductor devices such as solar cells,high-performance CMOS transistors,andⅢ-Ⅴ/Ⅳheterogeneous optoelectronic devices.The performance of these devices is di...GaAs/Ge heterostructures have been employed in various semiconductor devices such as solar cells,high-performance CMOS transistors,andⅢ-Ⅴ/Ⅳheterogeneous optoelectronic devices.The performance of these devices is directly dependent on the material quality of the GaAs/Ge heterostructure,while the material quality of the epitaxial GaAs layer on the Ge is limited by issues such as the antiphase domain(APD),and stacking-fault pyramids(SFP).We investigate the epitaxial growth of high-quality GaAs on a Ge(001)mesa array,via molecular beam epitaxy.Following a systematic study of the Ge terrace via an in situ scanning tunneling microscope,an atomically step-free terrace on the Ge mesa measuring up to 5×5μm^(2) is obtained,under optimized growth conditions.The step-free terrace has a single-phase c(4×2)surface reconstruction.The deposition of a high-quality GaAs layer with no APD and SFP is then achieved on this step-free Ge terrace.High-resolution transmission electron microscopy and electron channel contrast image characterizations reveal the defect-free growth of the GaAs layer on the step-free Ge mesa.Furthermore,InAs quantum dots on this GaAs/Ge mesa reveal photoluminescent intensity comparable to that achieved on a GaAs substrate,which further confirms the high quality of the GaAs layer on Ge.展开更多
基金the National Natural Science Foundation of China under Grant Nos.61635011,61975230,61804177,11434041 and 11574356the National Key Research and Development Program of China(2016YFA0300600 and 2016YFA0301700)+1 种基金the Key Research Program of Frontier Sciences,CAS(No.QYZDB-SSW-JSC009)Ting Wang is supported by the Youth Innovation Promotion Association of CAS(No.2018011).
文摘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.
基金Supported by the National Natural Science Foundation of China(Grant Nos.61975230,61635011,61804177 and 11804382)the National Key Research and Development Program of China(Grant No.2018YFB2200104)+1 种基金Beijing Municipal Science and Technology Commission(Grant No.Z191100004819010)the Key Research Program of Frontier Sciences,CAS(Grant No.QYZDB-SSW-JSC009)。
文摘GaAs/Ge heterostructures have been employed in various semiconductor devices such as solar cells,high-performance CMOS transistors,andⅢ-Ⅴ/Ⅳheterogeneous optoelectronic devices.The performance of these devices is directly dependent on the material quality of the GaAs/Ge heterostructure,while the material quality of the epitaxial GaAs layer on the Ge is limited by issues such as the antiphase domain(APD),and stacking-fault pyramids(SFP).We investigate the epitaxial growth of high-quality GaAs on a Ge(001)mesa array,via molecular beam epitaxy.Following a systematic study of the Ge terrace via an in situ scanning tunneling microscope,an atomically step-free terrace on the Ge mesa measuring up to 5×5μm^(2) is obtained,under optimized growth conditions.The step-free terrace has a single-phase c(4×2)surface reconstruction.The deposition of a high-quality GaAs layer with no APD and SFP is then achieved on this step-free Ge terrace.High-resolution transmission electron microscopy and electron channel contrast image characterizations reveal the defect-free growth of the GaAs layer on the step-free Ge mesa.Furthermore,InAs quantum dots on this GaAs/Ge mesa reveal photoluminescent intensity comparable to that achieved on a GaAs substrate,which further confirms the high quality of the GaAs layer on Ge.