Toward thin GaSb Buffer Layers Grown on On‐Axis (001) Silicon by Molecular Beam Epitaxy

• Published in: Advanced Physics Research Vol. 4; no. 1
• Main Authors: Gilbert, A., Ramonda, M., Patriarche, G., Tournié, E., Rodriguez, J.‐B.
• Format: Journal Article
• Language: English
• Published: Edinburgh John Wiley & Sons, Inc 01.01.2025; Wiley; Wiley-VCH
• Subjects: Antiphase boundaries; antiphase domain; Buffer layers; Crystal defects; Crystal dislocations; Engineering Sciences; Epitaxial growth; gallium antimonide; Gallium antimonides; Gallium arsenide; III‐V on Si; Integrated circuits; Materials; Microscopy; Molecular beam epitaxy; semiconductor; Silicon; Silicon substrates; Thin films; Threading dislocations; Molecular beam epitaxy; Semiconductor; Gallium antimonide; III-V on Si; antiphase domain; Gallium arsenide
• ISSN: 2751-1200; 2751-1200
• DOI: 10.1002/apxr.202400090

The monolithic integration of III‐Vs on Silicon (Si) is of great interest for the development of active photonic integrated circuits (PICs). The main challenge is to achieve a high‐quality epitaxy of the III‐V on the Si substrate, as the differences between the materials are responsible for the formation of crystal defects, in particular threading dislocations (TDs) and antiphase domains (APDs) delineated by antiphase boundaries (APBs), which degrade the device's performance. A new technique is demonstrated to achieve thin APBs‐free GaSb buffer layers grown on Si substrates. The original idea presented in this paper is to introduce a GaAs layer into the buffer to promote faster burial of APDs. Two strategies are compared; the first one involves the complete APDs burying in GaAs before growing GaSb, while the second one uses a thin GaAs layer before burying the APDs in the GaSb layer. APB‐free buffer layers as thin as 215/400 nm have been obtained using the first method, which represents a factor of 2/4 thickness reduction compared to the previous results for both 0.5° and 0.2° miscut angles. An original strategy is presented to achieve thin antiphase boundaries‐free GaSb layers on Silicon(001) by introducing a GaAs layer in the buffer to promote fast and complete antiphase domains burying in terrace‐driven initial phase distribution. Structures as thin as 215–400 nm are demonstrated, representing a thickness reduction of 2–4 times compared to our previous results on 0.5° and 0.2° miscut angles.