Epitaxial Growth of Tensile Strained SiB Alloy on a Si Substrate

In this work, we present the first results of successful epitaxial growth of fully strained SiB alloy epilayers by RP-CVD. The epilayers were grown using standard and widely used Si and B gaseous precursors, diborane and disilane. Figure 1 shows a schematic cross section of the structures grown, which consist of a SiB epilayer grown directly on a Si (100) substrate. The thickness of SiB was varied from ~10 up to ~100 nm and the boron concentration was also varied. Comprehensive structural characterization was carried out using Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), Secondary Ion Mass Spectrometry (SIMS) and high resolution X-ray diffraction (HR-XRD). Figure 2 shows typical HR-XRD (004) rocking curves measured on two samples containing fully strained ~ 100 nm thick SiB epilayers of different B content. The peak positions, and presence of fringes, indicates tensile strain in the SiB alloy epilayers and a B content above 1 %.