Other

Zhang, PF,Nagle, RE,Deepak, N,Povey, IM,Gomeniuk, YY,O'Connor, E,Petkov, N,Schmidt, M,O'Regan, TP,Cherkaoui, K,Pemble, ME,Hurley, PK,Whatmore, RW

2011

January

The structural and electrical properties of the SrTa2O6/In0.53Ga0.47As/InP system

Validated

1

()

Atomic vapour deposition Strontium tnatalate MIS structures Gallium compounds Transmission electron microscopy III-V semiconductors Indium compounds Leakage currents

The structural and electrical properties of SrTa2O6(SrTaO)/n-In0.53GaAs0.47(InGaAs)/InP structures where the SrTaO was grown by atomic vapor deposition, were investigated. Transmission electron microscopy revealed a uniform, amorphous SrTaO film having an atomically flat interface with the InGaAs substrate with a SrTaO film thickness of 11.2 nm. The amorphous SrTaO films (11.2 nm) exhibit a dielectric constant of similar to 20, and a breakdown field of > 8 MV/cm. A capacitance equivalent thickness of similar to 1 nm is obtained for a SrTaO thickness of 3.4 nm, demonstrating the scaling potential of the SrTaO/InGaAs MOS system. Thinner SrTaO films (3.4 nm) exhibited increased non-uniformity in thickness. From the capacitance-voltage response of the SrTaO (3.4 nm)/n-InGaAs/InP structure, prior to any post deposition annealing, a peak interface state density of similar to 2.3 x 10(13) cm(-2) eV(-1) is obtained located at similar to 0.28 eV (+/- 0.05 eV) above the valence band energy (E-v) and the integrated interface state density in range E-v + 0.2 to E-v + 0.7 eV is 6.8 x 10(12) cm(-2). The peak energy position (0.28 +/- 0.05 eV) and the energy distribution of the interface states are similar to other high-k layers on InGaAs, such as Al2O3 and LaAlO3, providing further evidence that the interface defects in the high-k/InGaAs system are intrinsic defects related to the InGaAs surface. (c) 2011 Elsevier B.V. All rights reserved.

1054

1057

DOI 10.1016/j.mee.2011.03.118