Growth Temperature Window and Self-Limiting Process in Sub-Atomic-Layer Epitaxy

Abstract

We have recently proposed a sub-atomic-layer epitaxy (SALE) technique by which Si is grown submonolayer-by-submonolayer from Si2H6 on Si(001). In this technique, Si submonolayer adsorption and surface thermal excitation are repeated alternately and an atomically flat surface is obtained in every growth cycle. In this work, SALE growth has been carried out using resistive substrate heating and Ar+ laser irradiation for the thermal surface excitation and the role of the laser irradiation and the relationship between the growth conditions and the growth mode have been quantitatively investigated. The results indicate a substrate temperature window of ∼17±4° C the presence of which has been interpreted in terms of a self-limiting process in the SALE growth. When 5–7 Ω· cm p-type Si(001) substrate is used, a change of the laser power by 0.2 W shifts the substrate temperature window by ∼10±4° C which is in reasonable agreement with the value of ∼12° C estimated using the result of thermally decomposed CVD growth, indicating that the laser irradiation has primarily a thermal effect. The growth mode is controlled by the surface temperature which is controlled by the combination of the Ar+ laser irradiation and the resistive heating.