Secondary-ion mass spectrometry analysis in pseudomorphic GaAs/InGaAs/GaAs heterostructures utilizing a δ-doping superlattice

Significant improvement on two-dimensional electron gas (2DEG) concentration and mobility in a δ-doping superlattice GaAs/In _0.25Ga_0.75As/GaAs pseudomorphic heterostructures prepared by low-pressure metalorganic chemical vapor deposition have been demonstrated and discussed. The secondary-ion mass spectrometry profiles of these δ-doping superlattice structures were studied. The triple and double δ-doping superlattice heterostructures showed extremely high 2DEG concentrations of 8.8 (6.0) and 4.3 (2.5)×10¹² cm^-2 along with enhanced mobilities of 2710 (6500) and 3916 (18400) cm²/V s at 300 (77) K, respectively. The 2DEG concentrations, to our knowledge, are among the highest for previously reported pseudomorphic heterostructures with similar mobilities.