Atomic layer epitaxy of Si on Ge(100) using Si₂Cl₆ and atomic hydrogen

Abstract

The surface composition is measured during atomic layer epitaxy (ALE) growth of Si on Ge(100) using Si2Cl6 and atomic hydrogen (Hat) at TS=400°C. During each Si2Cl 6 exposure, Si is adsorbed until Cl fully terminates the surface, making the Si deposition step self-limiting. The terminating Cl layer is removed by Hat exposure. At 400°C, H2 rapidly desorbs from Ge(100) and Si/Ge alloy surfaces, regenerating the surface dangling bonds for the next Si2Cl6 adsorption cycle. A thin alloy is grown epitaxially on the Ge(100) substrate, which displays a linear increase in Si content and a linear decrease in Ge content, measured over 1-20 Si ALE cycles.