Low-temperature pathways to Ge-rich Si1−xGex alloys via single-source hydride chemistry

Abstract

We report rapid low-temperature (300–470°C) growth of Si0.50Ge0.50, Si0.33Ge0.67, Si0.25Ge0.75, and Si0.20Ge0.80 alloys on Si(100) using heavy single-source hydride molecular compounds (H3Ge)nSiH4−n (n=1–4). Incorporation of the entire SiGe, SiGe2, SiGe3, and SiGe4 framework of these precursors into the film provides precise control of morphology, composition, and strain. Low-energy electron microscopy analysis indicates that the (H3Ge)xSiH4−x (x=2–4) species are highly reactive, with H2 desorption characteristics comparable to those of Ge2H6, despite the presence of strong Si–H bonds in their molecular structure.