Very Low Temperature Epitaxy of Heavily In-situ Phosphorous Doped Ge Layers and High Sn Content GeSn Layers

Abstract

We have studied at temperatures 350 °C and less, the 100 Torr epitaxy of heavily in-situ phosphorous doped Ge and high Sn content (> 6 %) GeSn alloys in a 200 mm industrial Reduced Pressure - Chemical Vapor Deposition tool. A dedicated low temperature Ge precursor, digermane (Ge2H6), was used here in order to promote Sn or P incorporation. We have first of all quantified the impact of the phosphine (PH3) flow on the structural and electrical properties of Ge:P layers. We have then investigated the epitaxy of high Sn content GeSn binaries with tin tetrachloride (SnCl4).