Gas Heterostructures Research Articles

Influence of RIE-induced damage on luminescence and electron transport properties of AlGaAs-GaAs heterostructures

Reactive ion etching induced damage was systematically studied by photoluminescence (PL), cathodoluminescence (CL) and electronic microwave absorption in GaAs/AlGaAs multiple quantum well (MQW) and two-dimensional electron gas (2DEG) heterostructures. Using QW’s of differing widths at various depths, PL and CL characterization of the individual quantum wells allowed a depth sensitive detection of RIE induced damage. Etching was done with CC12F2 at constant pressure and exposure time, while the bias voltage was successively increased from 55 to 320 V. A remarkable degradation in PL-intensity was observed for the topmost 1 nm QW located 30 nm beneath the surface, even at the lowest etch bias voltage. In 2DEG heterostructure samples investigated electrically, both mobility and carrier concentration of the 2DEG were seen to be strongly reduced. After illumination however, the initial values were almost completely restored, indicating that RIE damage predominantly reduces the electron supply efficiency of the AlGaAs barrier, whereas the 2DEG channel itself is not severely degraded even at the highest etch bias voltage.

IIA-3 a double two-dimensional electron gas heterostructure of GaAs-AlGaAs grown by MBE

IIA-3 a double two-dimensional electron gas heterostructure of GaAs-AlGaAs grown by MBE

Single-interface enhanced mobility structures by metalorganic chemical vapour deposition

Enhanced mobility effects in single-interface 2-dimensional electron gas heterostructures grown by metalorganic chemical vapour deposition (MOCVD) are reported. The mobility/temperature characteristics of single-interface structures, with and without an undoped spacer to reduce coulomb scattering at the interface, are described.