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An ambient pressure cell is described for conducting synchrotron-based x-ray photoelectron spectroscopy (XPS) measurements during atomic layer deposition (ALD) processes. The instrument is capable of true in situ and operando experiments in which it is possible to directly obtain elemental and chemical information from the sample surface using XPS as the deposition process is ongoing. The setup is based on the ambient pressure XPS technique, in which sample environments with high pressure (several mbar) can be created without compromising the ultrahigh vacuum requirements needed for the operation of the spectrometer and the synchrotron beamline. The setup is intended for chemical characterization of the surface intermediates during the initial stages of the deposition processes. The SPECIES beamline and the ALD cell provide a unique experimental platform for obtaining new information on the surface chemistry during ALD half-cycles at high temporal resolution. Such information is valuable for understanding the ALD reaction mechanisms and crucial in further developing and improving ALD processes. We demonstrate the capabilities of the setup by studying the deposition of TiO2 on a SiO2 surface by using titanium(IV) tetraisopropoxide and water as precursors. Multiple core levels and the valence band of the substrate surface were followed during the film deposition using ambient pressure XPS. [ABSTRACT FROM AUTHOR]

Copper thin films were grown on reduced indium tin oxide, molybdenum and polymer substrates using successive ionic layer adsorption and reaction (SILAR) method. Copper films were grown sequentially in a controlled way using simple copper salt and basic solution of formaldehyde as precursors. The copper films were polycrystalline with no preferred orientation as characterised by X-ray diffraction. On all substrates, the growth was clearly island growth in the beginning but after the whole surface was covered, the growth was more homogeneous. [Copyright &y& Elsevier]

This work examines the structural and electrical properties of HfSixOy film based metal-insulator-semiconductor capacitors by means of x-ray diffraction, x-ray photoelectron spectroscopy, capacitance-voltage (C-V), deep level transient spectroscopy, and conductance transient (G-t) techniques. Hafnium-rich silicate films were atomic layer deposited onto HF-etched or SiO2 covered silicon. Although as-deposited samples exhibit high interfacial state and disorder-induced gap state densities, a postdeposition thermal annealing in vacuum under N2 flow for 1 min at temperatures between 600 and 730 °C clearly improves the interface quality. Marked crystallization and phase separation occurred at 800 °C, increasing the structural heterogeneity and defect density in the dielectric oxide layers. [ABSTRACT FROM AUTHOR]

ZrO[sub 2] thin films with thicknesses below 20 nm were deposited by the atomic layer deposition process on Si(100) substrates at 350 °C. An organometallic precursor, Cp[sub 2]Zr(CH[sub 3])[sub 2] (Cp=cyclopentadienyl, C[sub 5]H[sub 5]) was used as the zirconium source and water or ozone as oxygen source. The influence of oxygen source and substrate pretreatment on the dielectric properties of ZrO[sub 2] films was investigated. Structural characterization with high-resolution transmission electron microscopy was performed to films grown onto HF-etched or native oxide covered silicon. Strong inhibition of ZrO[sub 2] film growth was observed with the water process on HF-etched Si. Ozone process on HF-etched Si resulted in interfacial SiO[sub 2] formation between the dense and uniform film and the substrate while water process produced interfacial layer with intermixing of SiO[sub 2] and ZrO[sub 2]. The effective permittivity of ZrO[sub 2] in Al/ZrO[sub 2]/Si/Al capacitor structures was dependent on the ZrO[sub 2] layer thickness and oxygen source used. The interfacial layer formation increased the capacitance equivalent oxide thickness (CET). CET of 2.0 nm was achieved with 5.9 nm ZrO[sub 2] film deposited with the H[sub 2]O process on HF-stripped Si. The ozone-processed films showed good dielectric properties such as low hysteresis and nearly ideal flatband voltage. The leakage current density was lower and breakdown field higher for the ozone-processed ZrO[sub 2] films. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

In this report we cover two special applications of Atomic Layer Deposition (ALD) thin films to solve these challenges of the very small size pixel detectors. First, we propose to passivate the p-type pixel detector with ALD grown Al 2 O 3 field insulator with a negative oxide charge instead of using the commonly adopted p-stop or p-spray technologies with SiO 2 , and second, to use plasma-enhanced ALD grown titanium nitride (TiN) bias resistors instead of the punch through biasing structures. Surface passivation properties of Al 2 O 3 field insulator was studied by Photoconductive Decay (PCD) method and our results indicate that after appropriate annealing Al 2 O 3 provides equally low effective surface recombination velocity as thermally oxidized Si/SiO 2 interface. Furthermore, with properly designed annealing steps, the TiN thin film resistors can be tuned to have up to several MΩ resistances with a few µm of physical size required in ultra-fine pitch pixel detectors. [ABSTRACT FROM AUTHOR]

15 N nuclear reaction analysis (NRA) for H is combined with 1.2 MeV deuteron (D) NRA which provides a simultaneous analysis for Li, Be, B, C, N, O and F. The energy dependence of the D NRA has been measured and used to correct for the D energy loss in film being analyzed. A 2 MeV He RBS measurement is made. Film composition is determined by a self-consistent analysis of the light element NRA data combined with an RBS analysis for heavy elements. This composition is used to simulate, with no adjustable parameters, the complete RBS spectrum. Comparison of this simulated RBS spectrum with the measured spectrum provides a powerful check of the analysis. [ABSTRACT FROM AUTHOR]

In this work we examine the structural and electrical properties including the memory performance of Al 2 O 3 /Si 3 N 4 /SiO 2 dielectric stacks implanted with low-energy nitrogen ions and subsequently thermal annealed at 850 or 1050 °C for 15 min. X-ray photoelectron spectroscopy reveals that the concentration and the chemical state of the nitrogen atoms within the Al 2 O 3 layer depends on the post-implantation annealing (PIA) temperature. Memory testing, performed on platinum gate capacitors, shows that charge retention of the programmed states is significantly improved for the high-temperature PIA samples as compared to the non-implanted samples. While such an improvement is not detected for the low-temperature PIA samples, the latter exhibit enhanced hole charging and thus, increased erase efficiency. Overall, our results suggest that the transport properties which control the erase and the retention characteristics of the blocking Al 2 O 3 layer can be tailored by nitrogen implantation and the PIA conditions and can be used for memory performance optimization. [ABSTRACT FROM AUTHOR]

Holmium titanium oxide (HoTiO x ) thin films of variable chemical composition grown by atomic layer deposition are studied in order to assess their suitability as dielectric materials in metal–insulator–metal electronic devices. The correlation between thermal and electrical stabilities as well as the potential usefulness of HoTiO x as a resistive switching oxide are also explored. It is shown that the layer thickness and the relative holmium content play important roles in the switching behavior of the devices. Cycled current–voltage measurements showed that the resistive switching is bipolar with a resistance window of up to five orders of magnitude. In addition, it is demonstrated that the post-breakdown current–voltage characteristics in HoTiO x are well described by a power-law model in a wide voltage and current range which extends from the soft to the hard breakdown regimes. [ABSTRACT FROM AUTHOR]

The post-breakdown conduction characteristics of holmium titanium oxide (HoTiO x )-based metal–insulator–metal capacitors fabricated by the atomic layer deposition technique on Si substrates were investigated. Diode-like and power-law models were fitted to the experimental current–voltage ( I – V ) curves and the results assessed with the aim of detecting any possible correlation among the model parameters. It was found that the number of parameters involved can be reduced in both cases and that for the power-law model a single parameter is solely required to approximate the I – V curves in a wide current range (from 10 −11 to 10 −4 A). This property, which has also been observed in a variety of material systems, was used to simulate the bipolar switching behavior exhibited by the I – V characteristics. The connection with the physics of electron transport through atom-sized constrictions is discussed. [ABSTRACT FROM AUTHOR]

Abstract: Stopping cross sections of atomic layer deposited Al2O3 and Ta2O5 and of Si3N4 for 0.03–1MeV/u 12C, 16O, 35Cl, 79Br and 127I ions have been measured by the transmission technique employing a Time of Flight-Elastic Recoil Detection Analysis (ToF-ERDA) setup. Simulation of experimental slowing down energy spectra was employed to obtain stopping cross section curves over a continuous energy range. The experimental results are compared with the predictions of the SRIM2012 parameterization and literature data. [Copyright &y& Elsevier]

The article presents a study on the damage induced by intense X-ray beam on diffractive X-ray optics. The study uses X-ray diffraction to monitor the gratings' diffraction efficiency as a function of irradiation and scanning electron microscopy (SEM) to evaluate the beam-induced damage. Results show that a vacuum environment could slow down the damage induced by beams and reduces its effect on the diffraction efficiency while diffractive X-ray optics must avoid organic compounds.