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In this work, we present experimental results examining the energy distribution of the relatively high ͑Ͼ1 ϫ 10 11 cm −2 ͒ electrically active interface defects which are commonly observed in high-dielectric-constant ͑high-k͒ metal-insulator-silicon systems during high-k process development. This paper extends previous studies on the Si͑100͒/SiO x /HfO 2 system to include a comparative analysis of the density and energy distribution of interface defects for HfO 2 , lanthanum silicate ͑LaSiO x ͒, and Gd 2 O 3 thin films on ͑100͒ orientation silicon formed by a range of deposition techniques. The analysis of the interface defect density across the energy gap, for samples which experience no H 2 /N 2 annealing following the gate stack formation, reveals a peak density ͑ϳ2 ϫ 10 12 cm −2 eV −1 to ϳ1 ϫ 10 13 cm −2 eV −1 ͒ at 0.83-0.92 eV above the silicon valence bandedge for the HfO 2 , LaSiO x , and Gd 2 O 3 thin films on Si͑100͒. The characteristic peak in the interface state density ͑0.83-0.92 eV͒ is obtained for samples where no interface silicon oxide layer is observed from transmission electron microscopy. Analysis suggests silicon dangling bond ͑ P bo ͒ centers as the common origin for the dominant interface defects for the various Si͑100͒/SiO x /high-k/metal gate systems. The results of forming gas ͑H 2 /N 2 ͒ annealing over the temperature range 350-555°C are presented and indicate interface state density reduction, as expected for silicon dangling bond centers. The technological relevance of the results is discussed.

Response to "Comment on 'Broadening of metal-oxide-semiconductor admittance characteristics: Measurement, sources, and its effects on interface state density analyses'" [J. Appl. Phys. 112, 076101 (2012)] J. Appl. Phys. 112, 076102 (2012) Reduction in interface state density of Al2O3/InGaAs metal-oxide-semiconductor interfaces by InGaAs surface nitridation J. Appl. Phys. 112, 073702 (2012) Improved charge-trapping properties of TiON/HfON dual charge storage layer by tapered band structure Appl. Phys. Lett. 101, 133503 (2012) A model for internal photoemission at high-k oxide/silicon energy barriers Admittance spectroscopy is extended for measuring capacitance and conductance on metal-oxide-semiconductor ͑MOS͒ structures as a function of gate voltage, frequency, and temperature. An automatic setup has been designed for collecting data along these dimensions in one measurement cycle. The theory for admittance spectroscopy has been developed by starting from basic charge carrier statistics. Using numerical integration of energy dependent parameters instead of the commonly used analytical solution, conductance dispersion curves are obtained which do not need to be adjusted by assuming lateral surface potential variations at the oxide-semiconductor interface. Also, we find that interface state densities extracted by using traditional methods are four times lower than those obtained by using our theory. Experimental data presented in three-dimensional plots are compared with theoretical calculations, revealing the possibilities and limitations of the conductance method.

Using a method based on the frequency dependence of capacitance, cross sections for electron capture into energy states at the interlayer/silicon interface have been investigated for HfO2 that is deposited on silicon by reactive sputtering. We find that the capture cross sections are thermally activated and steeply increase with increasing energy depth. Both features can be attributed to the same physical origin, indicating vibronic trap properties, where the capture mechanism is governed by multiphonon processes.

P‐type Czochralski grown (Cz) silicon samples have been irradiated at room temperature (RT), 350, and 450 °C with 1.8 MeV protons to doses of 2×1012and 1×1013 cm‐2 and analyzed by deep level transient spectroscopy (DLTS). The generation rate of interstitial carbon–interstitial oxygen (CiOi) increases with the irradiation temperature, suggesting less efficient annihilation of self‐interstitials and mono‐vacancies at elevated temperature. A defect located at ∼Ev+0.39 eV (Ev denotes the valence band edge) appears in the sample irradiated at 450 °C and also emerges at the expense of CiOi center in the sample irradiated at RT and subsequently heat‐treated above 400 °C. The amplitude of this level is enhanced in the sample irradiated at 450 °C. By comparing the annealing behavior found by photoluminescence (PL) measurements and reported theoretical predictions, the ∼Ev+0.39 eV level is tentatively assigned to the interstitial carbon–oxygen dimer (CiO2i). In addition, other levels at ∼Ev+0.34 eV and ∼Ev+0.58 eV are observed in samples irradiated at 450 °C and RT with heat treatment in the range of 400‐500 °C (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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The formation of the divacancy-oxygen centre (V(2)O) in p-type Czochralski-grown silicon has been investigated by means of deep level transient spectroscopy (DLTS). The donor state (+/0) of V(2)O is located at ~E(v) + 0.23 eV (E(v) denotes the valence band edge) and emerges during heat treatment above 200 °C at the expense of the divacancy centre (V(2)). A concurrent transition takes place between the single-acceptor states of V(2) and V(2)O, as unveiled by the injection of electrons through optical excitation during the trap filling sequence of the DLTS measurements. Further, a defect with an energy level at ~E(v) + 0.09 eV evolves in close correlation with the growth of V(2)O but at a factor of ~5-6 lower in concentration. In the literature, the E(v) + 0.09 eV level has previously been attributed to a double-donor state of V(2)O but this assignment can be ruled out by the present data favouring a complex formed between migrating V(2) centres and a competing interstitial oxygen trap. In addition, a level at ~E(v) + 0.24 eV occurs also during the heat treatment above 200 °C and is tentatively assigned to the trivacancy-oxygen centre (V(3)O).