Selective epitaxial growth of Si1−x Ge x films via the alternating gas supply of Si2H6, GeH4, and Cl2: Effects of Cl2 exposure

Abstract: Si1−x Ge x films were epitaxially grown on Si(001) substrates at various ratios of flow rates of Si2H6 and GeH4. Si1−x Ge x films were also selectively grown on Si windows through modified alternating gas supply manner, repeating the unit cycle which consists of the Si1−x Ge x growth step and Cl2 exposure step. Injection of Cl2 enhanced the selectivity of the selective growth of Si1−x Ge x by etching away the spurious nuclei or deposits formed on oxide area. The separate addition of Cl2 resulted in decrease of the growth rate and Ge concentration of Si1−x Ge x film. Meanwhile, Ge concentration in Si1−x Ge x films was insignificantly affected by the variation of the flow rates and exposure durations of Cl2. [Copyright &y& Elsevier]