Experimentally Calibrated Modeling of Periodic Supply Epitaxy for Selective Area Growth by Molecular Beam Epitaxy

Selective area growth is key to the future advancement and design of optoelectronic devices by enabling the monolithic integration of laterally patterned semiconductors, dielectrics, and metals. However, molecular beam epitaxy has historically had low deposition selectivity, limiting its selective area regrowth capabilities. Periodic supply epitaxy, a selective molecular beam epitaxial growth technique, accounts for deposition on the mask surface by introducing interruptions into the group III flux to mitigate polycrystalline material growth, enabling the use of conditions closer to that of the ideal III–V growth regime and circumventing the limitations imposed by the low group-III adatom mobility on the amorphous mask surfaces. In this study, the selective growth mechanisms of PSE were observed and quantified under restricted GaAs growth conditions via a diffusion-based model that was calibrated experimentally through growth studies on unpatterned SiO2 films. The model calculates group-III adatom concentration on the surface of the amorphous feature to identify selective growth regimes and evaluate the influence of PSE conditions (deposition time, duty cycle, etc.). To demonstrate the predictive capabilities of this modeling approach, a feature-independent selective PSE regime for GaAs growth was predicted for the first time and confirmed experimentally.