Quantum-well Hall devices in Si-delta-doped Al0.25Ga0.75As/GaAs and pseudomorphic Al0.25 Ga0.75As/In0.25Ga0.75As/GaAs heterostructures grown by LP-MOCVD: performance comparisons

Characterized herein are quantum-well Hall devices in Si-delta-doped Al_0.25Ga_0.75As/GaAs and pseudomorphic Al_0.25Ga_0.75As/In_0.25Ga _0.75As/GaAs heterostructures, grown by low-pressure metal organic chemical vapor deposition method. The Si-delta-doping technique has been applied to quantum-well Hall devices for the first time. As a result high electron mobilities of 8100 cm^-2/V·s with a sheet electron density of 1.5×10¹² cm^-2 in Al_0.25Ga_0.75As/In_0.25Ga_0.75 As/GaAs structure and of 6000 cm^-2/V·s with the sheet electron density of 1.2×10¹² cm^-2 in Al_0.25Ga_0.75As/GaAs structure have been achieved at room temperature, respectively. From Hall devices in Al_0.25Ga_0.75As/In_0.25Ga_0.75 As structure, the product sensitivity of 420 V/AT with temperature coefficient of -0.015 %/K has been obtained. This temperature characteristic is one of the best result reported. Additionally, a high signal-to-noise ratio corresponding to the minimum detectable magnetic field of 45 nT at 1 kHz and 75 nT at 100 Hz has been attained. These resolutions are among the best reported results