RESONANT MAGNETOTUNNELING OF GEXSI1-X RESONANT TUNNELING STRUCTURES GROWN AT EXTREMELY LOW-TEMPERATURE BY MOLECULAR-BEAM EPITAXY

Resonant tunneling structures of GexSi1-x double barrier quantum wells were grown at different temperatures by molecular-beam epitaxy. Previously, the growth of very thick coherently strained GexSi1-x layers at extremely low temperature and low pressure was reported. Following this technique, strained well GexSi1-x resonant tunneling diodes with high Ge concentration are fabricated. For a strained structure with a higher Ge concentration, it is expected to have higher band offsets and lighter effective masses. A smaller leakage current and a better peak to valley ratio were found for the samples grown at low temperature. From magnetotunneling measurements, the effective masses of heavy and light holes under strain were obtained.