Minority Carrier Lifetime of GaAs on Silicon

The lifetime of minority carriers in GaAs grown heteroepitaxially on silicon is reduced two to three orders of magnitude by recombination at mismatch dislocations. Here we fabricated isotype double heterostructures for minority carrier lifetime diagnostics and transmission electron microscopy (TEM). The diagnostic structures were fabricated on strain reduction layers composed of annealed buffer layers and strained layers. Transmission electron microscopy (TEM) shows that an annealed buffer layer reduces the dislocation density over two orders of magnitude. The minority carrier lifetime in these double heterostructures is increased more than a factor of twenty. The minority carrier lifetime vs. dislocation density was described quite well by the model of Yamaguchi and co-workers.