High electron mobility in the selectively doped heterostructures grown by normal pressure metalorganic chemical vapor deposition

GaAs/AlGaAs heterostructure selectively doped with Si was grown in a conventional normal pressure metalorganic chemical vapor deposition using trimethyl metals and arsine. Mobility of the two-dimensional electron gas as high as 8100, 148 000, and 401 000 cm2/V s was obtained at 300, 77, and 5 K, respectively, for a sample with an undoped Al0.3Ga0.7As spacer layer of 100 Å and with a sheet electron density of about 5×1011 cm−2. The heterostructure with the spacer layer thinner than 100 Å shows high mobility comparable to the best values obtained by molecular-beam epitaxy. The influence of growth parameters on the electron mobility in the heterostructure is described in detail.