Two-dimensional electron gas formation in undoped In0.75Ga0.25As/In0.75Al0.25As quantum wells

We report on the achievement of a two-dimensional electron gas in completely undoped In0.75Al0.25As/In0.75Ga0.25As metamorphic quantum wells. Using these structures we were able to reduce the carrier density, with respect to reported values in similar modulation-doped structures, to about 2–3×1011 cm−2 with mobilities of up to 2.15×105 cm2 (V s)−1. We found experimentally that the electronic charge in the quantum well is likely due to a deep-level donor state in the In0.75Al0.25As barrier band gap, whose energy lies within the In0.75Ga0.25As/In0.75Al0.25As conduction band discontinuity. This result is further confirmed through a Poisson–Schrodinger simulation of the two-dimensional electron gas structure.

[1]  F. Maeda,et al.  Anomalous downward band bending induced by selenium passivation of MBE-grown InAs(001) surfaces , 1997 .

[2]  J. P. Zielinger,et al.  Photoinduced current transient spectroscopy in high‐resistivity bulk materials: Instrumentation and methodology , 1988 .

[3]  Band engineering at interfaces : Theory and numerical experiments , 1998 .

[4]  Jerry R. Meyer,et al.  Band parameters for III–V compound semiconductors and their alloys , 2001 .

[5]  C. Lavoie,et al.  RELATIONSHIP BETWEEN SURFACE MORPHOLOGY AND STRAIN RELAXATION DURING GROWTH OF INGAAS STRAINED LAYERS , 1995 .

[6]  Shin-ichirou Gozu,et al.  Very high electron mobilities at low temperatures in InxGa1−xAs/InyAl1−yAs HEMTs grown lattice-mismatched on GaAs substrates , 1999 .

[7]  Strain relaxation in high-mobility InAs inserted-channel heterostructures with metamorphic buffer , 2002 .

[8]  T. Matsuyama,et al.  Transport properties of modulation-doped InAs-inserted-channel In0.75Al0.25As/In0.75Ga0.25As structures grown on GaAs substrates , 2000 .

[9]  Snyder,et al.  Kinetically controlled critical thickness for coherent islanding and thick highly strained pseudomorphic films of InxGa1-xAs on GaAs(100). , 1992, Physical review. B, Condensed matter.

[10]  D. Grundler.  Large Rashba splitting in InAs quantum wells due to electron wave function penetration into the barrier layers. , 2000, Physical review letters.

[11]  R. H. Williams,et al.  The effect of growth temperature on the electrical properties of AlInAs/InP grown by molecular beam epitaxy and metal‐organic chemical‐vapor deposition , 1993 .

[12]  Patricia M. Mooney,et al.  Deep donor levels (DX centers) in III‐V semiconductors , 1990 .

[13]  Koch,et al.  Suppression of the Landau-level coincidence: A phase transition in tilted magnetic fields. , 1993, Physical review. B, Condensed matter.

[14]  Peter Blood,et al.  The Electrical Characterization of Semiconductors: Majority Carriers and Electron States , 1992 .

[15]  S. Mendach,et al.  Highly anisotropic electron transport in shallow InGaAs heterostructures , 2003 .

[16]  F. Romanato,et al.  Continuously graded buffers for InGaAs/GaAs structures grown on GaAs , 1997 .