Epitaxial Growth of Ge_(1-x)Sn_x by Reduced Pressure CVD Using SnCl_4 and Ge_2H_6

摘要

The epitaxial growth of Ge and GeSn on Si(100) is studied in the low temperature regime by reduced pressure chemical vapor deposition using showerhead technology. Most emphasis is placed on the growth kinetics in the low temperature regime of 375°C to 500°C which is characterized by surface limited reactions. Using Ge_2H_6 precursor low activation energy of 0.7 eV was determined for H_2 carrier gas which further decreases to 0.5 eV if N_2 is used. GeSn layers with 10 and 6.5 at.% Sn are obtained at growth temperatures of 375°C and 400°C respectively, using Ge_2H_6 and SnCl_4 as precursors. All Ge and GeSn layers are of high crystalline quality.