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

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 ∼20, and a breakdown field of >8 MV/cm. A capacitance equivalent thickness of ∼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 ∼2.3 × 1013 cm−2 eV−1 is obtained located at ∼0.28 eV (±0.05 eV) above the valence band energy (Ev) and the integrated interface state density in range Ev + 0.2 to Ev + 0.7 eV is 6.8 × 1012 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.

The structural and electrical properties of SrTa2O6(STaO)/n-In0.53GaAs0.47(InGaAs)/InP structures where the STaO was grown by atomic vapor deposition, were investigated. Transmission electron microscopy (TEM) and the multi-frequency capacitance-voltage (CV) were used to characterize these structures.Figure optionsDownload as PowerPoint slide