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JET Mk-II Gas Box divertor tiles exposed in 1998–2001 have been analysed with various ion beam techniques, secondary ion mass spectrometry (SIMS) and Raman spectroscopy. Inner divertor wall tiles removed in 2001 were covered with a duplex film. The inner layer was very rich in metallic impurities, with Be/C ∼ 1 and H-isotopes only present at low concentrations. The outer layer contained higher concentrations of D than normal for plasma-facing surfaces in JET (D/C ∼ 0.4), and Be/C ∼ 0.14. Raman and SIMS analyses show that the deposited films on inner divertor tiles are hydrogenated amorphous carbon with low sp 3 fractions. The deposits have polymeric structure and low density. Both Raman scattering and SIMS indicate that films on inner divertor wall Tiles 1 and 3, and on floor Tile 4 have some differences in the chemical structure of the deposited films

Tritium surface distribution on the JET Mark II Septum Replacement Plate (Mk II SRP) divertor tiles was measured by imaging plate technique. It was observed that areal tritium concentration was higher at the entrance of inner/outer pumping slots (so called ‘shadowed area’). The tritium distribution profiles were similar to those obtained in the Mk IIA divertor which was exposed to a series of D–T plasma operation (DTE1). Tritium concentration of the plasma facing surface was lower compared to that of the shadowed area. Particularly, it was very low at the outer divertor surface. The inner divertor surface also showed low level of tritium retention, though it was covered by the thick carbon deposition on that. This could be caused by tritium release due to the temperature rise when the inner strike point was on the tiles. On the plasma shadowed area like tile gaps, high tritium retention owing to the codeposition was observed.

Carbon-13 labelled methane was injected into the outer divertor during a series of H-mode discharges on the last day of operations with the JET MkII-SRP divertor. Tiles from around the vessel were removed during the subsequent shutdown and surface deposits were analysed by IBA techniques and SIMS. First attempts to model the pattern of 13 C deposition using EDGE2D are reported. Erosion of W markers at the outer divertor was observed, with implications for the ITER-like wall experiment planned for JET, whilst thin film growth in the same region has been followed by the effect on infrared measurements. The composition of thick films deposited at the inner divertor during the MkII-SRP campaign, and the migration to the inner corner of the divertor observed by a quartz micro-balance, provide further information on divertor transport. Crown Copyright (c) 2007 Published by Elsevier B.V. All rights reserved.

Deuterium retention in the implantation-induced defects in polycrystalline tungsten has been studied. Deuterium was implanted with different energies and concentrations of retained D were analysed with secondary ion mass spectrometry and nuclear reaction analysis. Annealings were carried out at four pre-determined temperatures corresponding to four different defect types that can trap deuterium. A quantitative number of each defect type produced by 5, 15 and 30 keV D implantation with a dose of 5.8×1016 cm−2 was obtained.

The interfacial integrity of a gate stack featuring a polycrystalline SiGe gate, an ultrathin Al2O3/HfO2/Al2O3 nano-laminate and a strained-SiGe surface-channel is examined for full transistor fabrication and characterization. The high-κ dielectric nano-laminate is prepared by means of atomic layer deposition, and the SiGe channel and gate by chemical vapor deposition. After full transistor-processing including a rapid thermal processing step at 930 °C, the 3 nm thick HfO2 film becomes polycrystalline whereas the Al2O3 films about 0.5 nm thick remain in the amorphous state, according to analyses using high-resolution and energy-filtering transmission electron microscopy. No interfacial reaction is observable between the HfO2 film and the SiGe gate or channel, since both interfaces are flat and the two Al2O3 films remain continuous. Well-behaving gate leakage and capacitance characteristics of the transistors are found. An enhanced channel hole mobility compared to the Si universal curve is obtained.

To investigate material transport in scrape-off layer plasma and in/out asymmetries in divertor, 13CH4 was puffed at the end of 2002/2003 experimental campaign into ASDEX Upgrade from the outer mid-plane. Ex-situ analyses of the tiles were performed by secondary ion mass spectrometry and Rutherford backscattering spectrometry. The highest amount of 13C was detected at the top of inner divertor, and below the inner and outer strike points towards the roof baffle. The 13C peaks below the strike points correlate with thick long term deposition layers detected in ion beam analysis experiments.

Carbon deposition and erosion were measured on ASDEX Upgrade divertor tiles and below the roof baffle during the operation period 2002/2003. The inner divertor is a net carbon deposition area, while a large fraction of the outer divertor is erosion dominated and the roof baffle tiles show a complicated distribution of erosion and deposition areas. In total, 43.7 g B + C were redeposited, of which 88% were deposited on tiles and 9% in remote areas (below roof baffle, on vessel wall structures). 0.6 g C was pumped out as volatile hydrocarbon molecules. Carbon sources in the main chamber are too low by a factor of more than ten to explain the observed carbon divertor deposition. Carbon erosion is observed at the outer divertor strike point tiles, but it is arguable if material can be transported from the outer strike point to the inner divertor.

A systematic study on the fluence (5 × 108 − 4 × 1014 cm−2) dependence of ion-implanted As diffusion in relaxed Si1 − xGex alloys (with x = 0.2, 0.35 and 0.5) and silicon has been performed by the modified radiotracer and secondary ion mass spectrometry techniques. With fluences above 4 × 1011 cm−2 a clear fluence-dependent enhancement in arsenic diffusion was noted for Si1 − xGex. In case of arsenic-implanted silicon such fluence dependency was not observed. This can be assigned to enhanced implantation-induced damage formation and more deficient radiation damage recovery of SiGe.

The atomic layer deposition (ALD) technique has been used to deposit different types of hafnium and zirconium silicates. The technique allows controlling the material thickness and quality due to atomic/molecular layer-by-layer growth mechanism. The films were deposited on 200 mm Si(1 0 0) substrates. Both thickness and Hf/Si or Zr/Si ratio were varied. Rutherford backscattering spectrometry and time-of-flight elastic recoil detection analysis were used to determine film composition and impurities distribution. Thickness and refractive index of the coatings were measured by spectroscopic ellipsometry. Our measurements showed the presence of photoluminescence in the Hf-silicate films.

We study Si–C films (Si content from 0 to 33 at. %) prepared with a pulsed arc discharge method. The structural modifications introduced by annealing up to 1100 °C, irradiation with 53 MeV 127I10+ ions, and deposition onto heated substrates are characterized by Raman spectroscopy. For all the treatments, the structural modifications decrease when the Si concentration increases. Moreover, for high Si content (33 at. %), the energetic iodine ions are found to recover efficiently the structure degraded in preliminary high-temperature annealing. The experiments demonstrate Si-induced stabilization of the three-dimensional Si–C network, which is interpreted as deepening of the corresponding potential energy well. It is highly possible that Si–C films can possess a superior thermodynamic stability for an optimal Si concentration.

Properties of physical vapor deposited diamond-like carbon films and the migration of hydrogen in co-deposited samples were studied. Measurements utilizing Rutherford backscattering spectrometry and Doppler-shift-attenuation techniques were used to obtain the average mass density of the films. Distributions of co-deposited hydrogen and deuterium were measured by the nuclear resonance reaction 1H (15N,αγ)12C, and the elastic recoil detection technique, respectively. Secondary ion mass spectrometry was also used in combination with these two methods. It was observed that in H and CH4 co-deposited DLC films the temperature of H release varied between 950 and 1070°C depending on the H concentration.

The stopping power of Mo, Cr, Cu and Ni for He ions at velocities below the Bohr velocity has been studied. The stopping power values were deduced by comparing ranges of 5–100 keV He$^{+}$-ions determined with the elastic-recoil-detection-analysis (ERDA) method with those obtained in molecular dynamics simulations. The nuclear slowing down was treated through the use of molecular dynamics calculations and a potential obtained from density-functional theory calculations. The comparisons of the range profiles showed that the electronic stopping powers given by J.F. Ziegler, J.P. Biersack and U. Littmark (The Stopping Powers and Ranges of Ions in Matter, vol. 1, Pergamon press, New York, 1985) had to be multiplied with a factor of 1.20 ± 0.07 for Mo and Cr and 1.00 ± 0.06 for Cu and Ni.

Compressively strained Si/sub 0.7/Ge/sub 0.3/ surface-channel pMOSFETs with atomic layer deposition (ALD) Al/sub 2/O/sub 3//HfO/sub 2//Al/sub 2/O/sub 3/ nanolaminate and low-pressure chemical vapor deposition p/sup +/ poly-SiGe gate electrode were fabricated. Surface treatment with either hydrogen fluoride (HF) clean, or HF clean followed by water rinse was performed prior to the ALD processing. The devices with water rinse show a good control of interfacial layer and device reproducibility, while the devices without water rinse lack a clearly observable interfacial layer and show scattered electrical characteristics and distorted mobility curve. A /spl sim/20% increase in hole mobility compared to the Si universal mobility and a /spl sim/0.6-nm-thick continuous interfacial layer are obtained for the pMOSFETs with water rinse.

Proof-of-concept pMOSFETs with a strained-Si/sub 0.7/Ge/sub 0.3/ surface-channel deposited by selective epitaxy and a TiN/Al/sub 2/O/sub 3//HfAlO/sub x//Al/sub 2/O/sub 3/ gate stack grown by atomic layer chemical vapor deposition (ALD) techniques were fabricated. The Si/sub 0.7/Ge/sub 0.3/ pMOSFETs exhibited more than 30% higher current drive and peak transconductance than reference Si pMOSFETs with the same gate stack. The effective mobility for the Si reference coincided with the universal hole mobility curve for Si. The presence of a relatively low density of interface states, determined as 3.3 /spl times/ 10/sup 11/ cm/sup -2/ eV/sup -1/, yielded a subthreshold slope of 75 mV/dec. for the Si reference. For the Si/sub 0.7/Ge/sub 0.3/ pMOSFETs, these values were 1.6 /spl times/ 10/sup 12/ cm/sup -2/ eV/sup -1/ and 110 mV/dec., respectively.

The interstitial to substitutional nitrogen atoms as a function of concentration in GaNAs were determined by nuclear reaction analysis utilizing the 14N(d,p)15N and 14N(d,α)12C reactions using ion channeling technique. The GaNAs films with mean nitrogen concentration between 0.3% and 3%, measured with secondary ion mass spectrometry and time-of-flight elastic recoil detection analysis, were grown using gas-source molecular-beam epitaxy. The fraction of nitrogen atoms occupying substitutional sites was observed to increase linearly with increasing nitrogen amount, while the concentration of interstitial nitrogen was nearly constant at 2×1019 cm−3 throughout the concentration region. Annealing at 750 °C decreases the concentration of interstitial nitrogen.

This addendum applies to papers authored by contributors from the Axially Symmetric Divertor Experiment (ASDEX) Upgrade Team published in Review of Scientific Instruments. This addendum provides the full list of ASDEX Upgrade Team contributors and their affiliations.

Erosion of tungsten in the outer JET divertor was determined with a set of tungsten coated divertor tiles during the 2001–2004 discharge campaign. The tungsten marker was strongly eroded, with the largest erosion at the outer strike point position, where more than 75% of the initial W disappeared. Strong erosion is also observed at the outer baffle and horizontal apron of tile 8, where about half of the tungsten has been removed. These numbers are lower boundaries, because the W was locally completely eroded. The tungsten erosion is inhomogeneous on a microscopic level and depends on the micro-topography of the rough surface: large erosion with complete disappearance of the W layer is observed on plasma-facing areas of microscopic ridges, while a smaller erosion and sometimes even deposition of carbon is found on the far side of ridges and in pores.

ASDEX Upgrade has recently finished its transition towards an all-W divertor tokamak, by the exchange of the last remaining graphite tiles to W-coated ones. The plasma start-up was performed without prior boronization. It was found that the large He content in the plasma, resulting from DC glow discharges for conditioning, leads to a confinement reduction. After the change to D glow for inter-shot conditioning, the He content quickly dropped and, in parallel, the usual H-Mode confinement with H factors close to one was achieved. After the initial conditioning phase, oxygen concentrations similar to that in previous campaigns with boronizations could be achieved. Despite the removal of all macroscopic carbon sources, no strong change in C influxes and C content could be observed so far. The W concentrations are similar to the ones measured previously in discharges with old boronization and only partial coverage of the surfaces with W. Concomitantly it is found that although the W erosion flux in the divertor is larger than the W sources in the main chamber in most of the scenarios, it plays only a minor role for the W content in the main plasma. For large antenna distances and strong gas puffing, ICRH power coupling could be optimized to reduce the W influxes. This allowed a similar increase of stored energy as yielded with comparable beam power. However, a strong increase of radiated power and a loss of H-Mode was observed for conditions with high temperature edge plasma close to the antennas. The use of ECRH allowed keeping the central peaking of the W concentration low and even phases of improved H-modes have already been achieved.

The erosion of tungsten and carbon marker layers was studied in the outer divertor of ASDEX Upgrade. The outer strike point area and a large fraction of the outer baffle are net erosion areas for both materials. The net erosion rate of carbon is about 10–20 times larger than the net erosion rate of tungsten. The erosion is strongly inhomogeneous due to surface roughness, with a large erosion on plasma exposed areas of the rough surfaces, and deposition in recessions and pores.

The deuterium inventory in ASDEX Upgrade was determined by quantitative ion beam analysis techniques and SIMS for different discharge campaigns between the years 2002 and 2005. ASDEX Upgrade was a carbon dominated machine during this phase. Full poloidal sections of the lower and upper divertor tile surfaces, limiter tiles, gaps between divertor tiles, gaps between inner heat shield tiles and samples from remote areas below the roof baffle and in pump ducts were analysed, thus offering an exhaustive survey of all relevant areas in ASDEX Upgrade. Deuterium is mainly trapped on plasma-exposed surfaces of inner divertor tiles, where about 70% of the retained deuterium inventory is found. About 20% of the inventory is retained at or below the divertor roof baffle, and about 10% is observed in other areas, such as the outer divertor and in gaps between tiles. The long term deuterium retention is 3–4% of the total deuterium input. The obtained results are compared with gas balance measurements, and conclusions about tritium retention in ITER are made.

To investigate material transport in scrape-off layer plasma and long term deposition in divertor, 13CH4 was puffed at the end of 2004 and 2005 experimental campaigns into ASDEX Upgrade from the outer mid-plane. Ex situ analyses of the tiles were performed by secondary ion mass spectrometry. The peaks of 13C were detected below the bottom inner strike point and at the horizontal tile at the outer lower divertor. It was detected ∼21% of the total puffed 13C amount. The deposition rate for carbon by plasma was also calculated in long term experiment. It was obtained to be 22 × 10−3 and 8.7 × 10−3 g/s for the upper (campaign 2004) and lower (campaign 2003) divertors, respectively.

Deposited layers formed on JET inner divertor tiles during 1998–2004 and 2001–2004 campaigns have been investigated using secondary ion mass spectrometry (SIMS), Rutherford Backscattering (RBS) and optical microscopy. The thickness of the deposit decreases from the top of vertical tile 1 to the bottom and then increases on vertical tile 3 reaching ∼60 μm. There are even thicker deposits on the small sloping section of the floor tile 4 that can be accessed by the plasma at the inner divertor legs. Deposited films on divertor inner wall tiles are enriched in Be indicating chemical erosion of C and a multi-step transport of C to the shadowed area on floor tile 4. The films have generally a layered and globular structure in the areas with plasma contact.

In the period 1998—2001 the JET tokamak was operated with the MkII Gas Box divertor. On two occasions during that period a number of limiter and divertor tiles were retrieved from the torus and then examined ex situ with surface sensitive techniques. Erosion and deposition patterns were determined in order to assess the material erosion, material migration and fuel inventory on plasma facing components. Tracer techniques, e.g. injection of 13C labelled methane and tiles coated with a low-Z and high-Z marker layer, were used to enhance the volume of information on the material transport. The results show significant asymmetry in the distribution of fuel and plasma impurity species between the inner (net deposition area) and the outer (net erosion) divertor channels. No significant formation of highly hydrogenated carbon films has been found in the Gas Box structure. The important processes for material migration, and the influence of operation scenarios on the morphology of the deposits are discussed. Comparison is also made with results obtained following previous divertor campaigns.

Tungsten has been proposed for first wall material in thermonuclear reactors, where its behaviour in the presence of hydrogen containing plasma irradiation at elevated temperatures is of key interest. Deuterium induced defects in polycrystalline tungsten have been studied. Deuterium was implanted into tungsten samples and retained D-concentrations were analyzed with nuclear reaction analysis and secondary ion mass spectrometry. We observed four different defect types that trap deuterium with release temperatures of 455, 560, 663 and 801 K. Total number of each defect type produced by 5.8 × 1016 cm−2 30-keV D implantation at room temperature was obtained to be 0.260, 0.156, 0.082 and 0.056 traps cm−2/implanted D atom.

In ASDEX Upgrade tungsten is used as a high-Z plasma facing material. Its erosion, migration and subsequent deposition have been studied by analysis of a set of customised marker tiles, which was installed in the divertor and at the central column for one experimental campaign. Erosion rates were determined at the central column, which was the main tungsten source in that campaign. Deposition rates were determined at the central column and in the divertor region. The W-deposition in the divertor is strongly correlated to the local strike point exposure time. In contrast to low-Z wall materials, where deposition occurs mainly in the inner divertor, tungsten is found in similar quantities also in the outer divertor. The total amount of tungsten deposited outside the central column is about 40% of the gross W-source at the central column. One possible explanation for the 60% undetected tungsten might be the prompt local redeposition of eroded W atoms.

During the campaign 2002–2003 a carbon erosion and deposition experiment was performed in the lower divertor of ASDEX Upgrade. A complete divertor cross section with erosion sensitive markers, deposition monitors below the divertor and time resolved measurements by quartz mircobalance monitors (QMB) and Langmuir probes are used. The largest amount of carbon deposition was found at the inner divertor target plates. At the outer divertor, erosion was observed. However, the behaviour at the outer strike point zone is not jet fully understood. The deposition at remote areas is concentrated below the divertor. Neutrals seem to be dominant at the layer formation at remote areas. Additional erosion of deposited layers by ions reduces the layer thickness dramatically at some locations. QMB data show that at the outer divertor, deposition and erosion occur at the same location, depending on the main plasma properties. A parasitic plasma is observed below the divertor.

Carbon erosion at the outboard divertor in ASDEX Upgrade has been investigated using the emission spectroscopy technique. The methane molecular influx was calibrated by simultaneous CD4 puffing. In deuterium H-mode discharges a decrease of D/XBCD←CD4 with increasing ion flux (decreasing temperature) is found at fluxes in the range 0.5–2 × 1022 m−2 s−1 and no dependence for higher fluxes. The corresponding obtained yields show a negative power law flux dependence with exponent γ = −0.46. To investigate the combined effect of re-deposition, re-erosion and local transport, known quantities of 13CH4 were puffed at the end of the 2002/2003 experimental campaign. The amount of 13C locally redeposited has been measured by nuclear reaction analysis (NRA). The results show a strongly localised re-deposition near the puff location, with a downstream tail and a moderate downward drift with respect to the magnetic field line direction.

ALD high-/spl kappa/ dielectrics and TiN metal-gate were successfully incorporated in both Si and Si/sub 0.7/Ge/sub 0.3/ surface-channel pMOSFETs. The high-/spl kappa/ gate dielectrics used included Al/sub 2/O/sub 3//HfAlO/sub x//Al/sub 2/O/sub 3/, Al/sub 2/O/sub 3//HfO/sub 2//Al/sub 2/O/sub 3/ and Al/sub 2/O/sub 3/. The Si transistors with Al/sub 2/O/sub 3//HfAlO/sub x//Al/sub 2/O/sub 3/ showed a sub-threshold slope of 75 mV/dec. and a density of interface states of 3/spl times/10/sup 11/ cm/sup -2/ eV/sup -1/. No obvious degradation of the Si channel hole mobility was observed. The Si/sub 0.7/Ge/sub 0.3/ pMOSFETs with the various high-/spl kappa/ gate dielectrics demonstrated enhanced transconductance, drive current and channel hole mobility compared with the Si reference.

Annealing behaviour of deuterium in carbon films with different Si contents deposited by a pulsed arc discharge method in deuterium atmosphere was studied. The concentration profiles of D were measured by secondary ion mass spectrometry and elastic recoil detection techniques. A model taking into account diffusion, detrapping and trapping of D is used to describe the experimental depth profiles. Diffusion coefficients obtained for non-trapped D resulted in activation energies of 1.5 ± 0.2, 0.7 ± 0.2, 0.6 ± 0.2 and 1.2 ± 0.2 eV for samples containing 0, 6, 15 and 33 at.% of Si, respectively.

EFDA CSU, European Fusion Development Agreement Close Support Unit, Max-Planck-Institut fu¨r Plasmaphysik,Boltzmannstrasse 2 D-85748 Garching bei Mu¨nchen, Germany~Received 4 May 2000; published 9 January 2001!Diffusion of deuterium in diamondlike carbon films with different Si contents deposited by a pulsed arcdischarge method in deuterium atmosphere was studied. The concentration profiles of D were measured bysecondary-ion-mass spectrometry and elastic-recoil-detection techniques. A model is proposed to describe theexperimental depth profiles. Diffusion, detrapping, and trapping of D were taken into account in this model.Diffusion coefficients obtained for nontrapped D resulted in activation energies of 1.560.2, 0.760.2, 0.660.2, and 1.260.2 eV for samples containing 0, 6, 15, and 33 at.% of Si, respectively.DOI: 10.1103/PhysRevB.63.045406 PACS number~s!: 66.30.Jt, 61.72.SsI. INTRODUCTION

Annealing behavior of implanted silicon in amorphous carbon films deposited by a pulsed arc discharge method was studied. Raman spectroscopy was used to characterize the changes in the bonding structure after annealing. The concentration profiles of Si were measured by secondary ion mass spectrometry (SIMS). The obtained diffusion coefficients resulted in an activation energy of 1.6±0.1 eV and pre-exponential factor of 1.9X104+1nm2s-1.

The diffusion of arsenic has been studied in 〈100〉 Ge, implanted with 1⋅1015, 120-keV 75As+ ions/cm2. The implanted samples were subjected to annealing in argon atmosphere in the temperature range of 450–550 °C. The annealing times varied between 0.5 and 91 h. The As concentration profiles were measured by secondary ion mass spectrometry. A Fermi-level-dependent diffusion of As atoms was observed and quantitatively explained by diffusion via Ge vacancies with charge states 0 and 2-. The activation energies and pre-exponential factors for As diffusion through neutral Ge vacancies was found to be 3.4±0.3 eV and 2.02×1020 nm2/s, respectively, and through doubly negatively charged vacancies 2.9±0.3 eV and 1.89×1016 nm2/s, respectively. The solid solubility limit of As increases with temperature from about 1×1019 cm−3 at 450 °C to about 5×1019 cm−3 at 550 °C.

Deuterium retention, solubility and out-diffusion have been studied in silicon doped carbon films produced by physical vapor deposition. The deuterium concentration profiles were measured by the time-of-flight elastic recoil detection analysis technique and secondary ion mass spectrometry. The D retention and solubility were measured in D implanted carbon samples. The out-diffusion of D was investigated in D co-deposited samples. The solubility of D was shown to increase as a function of Si concentration in the co-deposited samples while in the implanted samples no dependence of the Si content was observed. It was proposed that annealing behavior of deuterium has a trapping-like character.

The physical and electrical properties of HfSiO 4 dielectric layers deposited by atomic layer deposition (ALD) are reported. The precursor chemistries used for deposition were HfCl 4 /H 2 O for HfO 2 and NH 2 (CH 2 ) 3 Si(OC 2 H 5 ) 3 /O 3 for SiO 2 . Two processes with HfCl 4 :NH 2 (CH2)3Si(OC 2 H 5 )3 precursor pulse ratios of 5:1 (HfO 2 -rich) and 1:1 (SiO 2 -rich) are investigated. Measurements with X-ray photoelectron spectroscopy and channeling Rutherford backscattering spectrometry show that these processes result in layers with Hf/(Hf + Si) ratios of 0.56 and 0.34-0.37, respectively. X-ray diffraction measurements showed formation of a HfO 2 cubic phase in HfO 2 -rich layers starting at 850°C. In SiO 2 -rich layers, no crystallization was detected up to 1100°C. Metal oxide semiconductor (MOS) capacitors with polysilicon electrodes were used for electrical characterization. The k-value of the SiO 2 -rich layers was found to be 4.8-5.4 and that of the HfO 2 -rich layers 12.5-15.1, both with an experimental error of 10%. The leakage currents of both types of layers were comparable to SiO 2 reference data and increased with polysilicon activation anneal. A high-resolution transmission electron microscopy study revealed phase segregation in thick SiO 2 -rich layers. In HfO 2 -rich layers, the phase segregation was less clear, but upon annealing, composition variations at the interfaces were detected. Given the experimental errors, no impact of phase segregation on the k-values of both types of layers could be detected. It is concluded that postdeposition annealing of HfSiO 4 layers for application as gate dielectrics applications in advanced complementary MOS technologies is essential to optimize stoichiometry and reduce leakage currents.

The physical (growth rate, composition, crystallization) and electrical (C-V, I-V) properties of Zr-silicates deposited by atomic layer deposition are reported. Hf- and Zr-silicates are particularly attractive for use as gate dielectrics in advanced complementary metal-oxide-semiconductor (CMOS) technologies, because they exhibit high crystallization temperature and result in high carrier mobility at the Si interface. Zr-silicate layers with Zr:Si atom% ratios of 2:1 and 1:1 were deposited on Al 2 O 3 and SiO 2 , respectively. For these layers, we found k values of 7.5 ′ 0.8 and 13 ′ 1.3. Crystallization occurs at 1000 and 850°C, respectively. Based on these properties, it is concluded that Zr-silicate layers can be regarded as possible gate dielectrics in advanced CMOS technologies.