Selectively Se‐doped AlGaAs/GaAs heterostructures with reduced DX‐center concentrations grown by molecular‐beam epitaxy

We studied the DX centers in Se‐doped Alx Ga1−xAs layers grown by molecular‐beam epitaxy. The DX‐center concentrations of these layers were considerably lower than in Si‐doped layers because of their shallower DX‐center energy levels. We also studied Se doping of AlGaAs layers, and applied Se doping to selectively doped AlGaAs/GaAs heterostructures to eliminate the influences of DX centers. By optimizing growth conditions, we obtained excellent two‐dimensional electron gas characteristics comparable to those of conventional Si‐doped heterostructures. Using Se‐doped Al0.2 Ga0.8 As layers, we grew DX‐center‐free selectively doped AlGaAs/GaAs heterostructures having electron mobilities of 70 000 cm2 /V s at 77 K.

[1]  M. Suzuki,et al.  Se-doped AlGaAs/GaAs HEMTs for stable low-temperature operation , 1990, IEEE Electron Device Letters.

[2]  E. Yamaguchi.  The Origin of the DX Center in AlxGa1-xAs , 1986 .

[3]  Tohru Yamamoto,et al.  Formation of DX Centers by Heavy Si Doping in MBE-Grown AlxGa1-xAs with Low Al Content , 1986 .

[4]  Ohnishi,et al.  DX center: Crossover of deep and shallow states in Si-doped AlxGa1-xAs. , 1986, Physical Review B (Condensed Matter).

[5]  T. Drummond,et al.  Deep donor model for the persistent photoconductivity effect , 1986 .

[6]  R. Kiehl,et al.  On the low-temperature degradation of (AlGa)As/GaAs modulation-doped field-effect transistors , 1986, IEEE Transactions on Electron Devices.

[7]  M. Mizuta,et al.  Direct Evidence for the DX Center Being a Substitutional Donor in AlGaAs Alloy System , 1985 .

[8]  T. Baba,et al.  Thermal Stability of a Short Period AlAs/n-GaAs Superlattice , 1985 .

[9]  Y. Mori,et al.  Chemical trends in the activation energies of DX centers , 1984 .

[10]  K. Ploog,et al.  Shallow and deep donors in direct-gap n -type Al x Ga 1 − x A s : S i grown by molecular-beam epitaxy , 1984 .

[11]  T. Baba,et al.  Elimination of Persistent Photoconductivity and Improvement in Si Activation Coefficient by Al Spatial Separation from Ga and Si in Al–Ga–As:Si Solid System –a Novel Short Period AlAs/n-GaAs Superlattice– , 1983 .

[12]  Michael S. Shur,et al.  TEMPERATURE DEPENDENCE OF THE I-V CHARACTERISTICS OF MODULATION-DOPED FETs. , 1983 .

[13]  D. Lang,et al.  Trapping characteristics and a donor-complex ( DX ) model for the persistent-photoconductivity trapping center in Te-doped Al x Ga 1 − x As , 1979 .

[14]  C. Wood.  ’’Surface exchange’’ doping of MBE GaAs from S and Se ’’captive sources’’ , 1978 .

[15]  K. Kondo,et al.  Doping Study of Se into AlGaAs Layers Grown by MBE, and their Application to HEMT Structures , 1988 .