Growth Of TiN Films Research Articles

Pinning growth of TiN films toward porous Ti matrix

Pinning growth of TiN films toward porous Ti matrix

Surface Conductivity and Preferred Orientation of TiN Film for Ti Bipolar Plate

The properties of thin films are often influenced by the crystal’s preferred orientation. In the present study, we report the strong dependence of surface conductivity on the preferred orientation of TiN film that acts as the coating material for Ti bipolar plate. The preferred orientation of TiN film is successfully controlled along the (111) or (200) planes by adjusting the N2 flow rate or Ti substrate temperature during the deposition process via DC (direct current) reactive magnetron sputtering. Small N2 flow rate of 3 to 6 sccm or low substrate temperature (e.g., 25 °C) facilitates the growth of TiN films along the (111). The (111) preferred orientated TiN films show much lower interfacial contact resistance (ICR) than the (200) preferred orientated films. A considerably low ICR value of 1.9 mΩ·cm2 at 140 N/cm2 is achieved at the N2 flow of 4 sccm and the substrate temperature of 25 °C.

Epitaxial growth of TiN on (0001) semi-insulating 4H-SiC substrate by reactive sputtering

Growth of epitaxial TiN film on a semi-insulating single crystal (0001) SiC substrate has been achieved by DC magnetron reactive sputtering deposition. The effects of growth temperature and N2 flow ratio in Ar on film quality and growth rate were investigated. X-ray diffraction (XRD) characterization shows that all the deposited TiN films at 550 and 700 °C are heteroepitaxially grown on SiC with the epitaxial relationship between TiN and 4H-SiC in (111)TiN//(0001)SiC and [11¯0]TiN//[112¯0]4H-SiC. Increasing the N2 flow ratio from 4 to 8% results in improvement of the film quality and a decrease in the growth rate. The width of the X-ray rocking curve of TiN (111) reflection can reach a value as small as 249 arcsec and the resistivity of TiN film can be 21 μΩ·cm for deposition at 700 °C with 8% N2 flow ratio. Measurements by atomic force microscopy show that the surface roughness of the TiN film can be 1.1 nm. X-ray photoelectron spectroscopy reveals that TiN composition is nearly in stoichiometry for all the grown TiN films. Examinations by cross-sectional transmission electron microscopy show that TiN is directly grown on SiC and verify the epitaxial relationship from XRD.

Study on TiN film growth mechanism using spectroscopic ellipsometry

Study on TiN film growth mechanism using spectroscopic ellipsometry

Conformal and Smooth TiN Film Growth By Using ALD Method

As the generation of memory devices evolve, the successful fabrication of high aspect ratio (HAR) features becomes more and more challenging. Apart from the traditional patterning, deposition and etch related issues, conformal film deposition onto these HAR structures becomes a critical parameter in determining the overall device yields. It is well established now that compared to conventional deposition techniques such as chemical vapor deposition (CVD) and physical vapor deposition (PVD), atomic layer deposition (ALD) offers a pathway to highest conformality and step-coverage. On the other hand, film conformality, especially roughness property has trade-off relationship to step-coverage property. High-pressure process is appropriate to obtain high step-coverage performance in short ALD cycle time process, but roughness value becomes worse due to higher chance of crystalline film growth at high-pressure process condition. High roughness causes local variations in step-coverage and poses problems for deposition of subsequent layers and device performance.In the present study, we report that it is possible to obtain conformal and smooth TiN film by using low/high pressure two-step growth, initially low-pressure TiN growth, and secondly high-pressure TiN growth on the non-pattern and HAR pattern wafers. Eugenus’s versatile 300mm mini-batch system and HAR structures with approximately 120:1 (Dimension of bottom opening, and total height are approximately 17nm and 2μm, respectively) were used in this research, respectively. TiCl4 and NH3 were used as the precursors for TiN film deposition and grown TiN films were analyzed by using ellipsometry, atomic force microscopy (AFM) and transmission electron microscopy (TEM) to study the film properties and step-coverages. In addition, reactor-scale computational fluid dynamics (CFD) simulations were performed and correlated to on-wafer experimental results and utilized as a predictive tool.It was found that TiN film grown at low-pressure condition was more conformal and smoother than that grown at high-pressure condition, although step coverage value grown at low-pressure condition was worse than that grown at high-pressure condition. By optimizing low/high pressure two-step TiN growth condition, it was achieved that not only better roughness than that of pure high-pressure TiN, but also, better step coverage value than that of pure low-pressure TiN as well as than that of pure high-pressure TiN (Figure 1). Figure 1

The effect of NH3 plasma pulse time on atomic layer-deposited TiN films using tetrakis-(dimethylamino) titanium as a metal precursor

The growth of TiN films by plasma-enhanced atomic layer deposition is investigated using tetrakis-(dimethylamino) titanium and NH3. In particular, the influence of the NH3 plasma pulse time on the deposited film is discussed in detail. It is found that the film resistivity decreases monotonically to 4.6 × 10−4 Ω · cm by increasing the NH3 plasma pulse time to 25 s, then shows an increase. The former trend is ascribed to some competitive reactions dominated by N radicals and residual O2, i.e., more N radicals originating from longer NH3 plasma pulses produce more Ti–N bonds and restrain the formation of Ti–O and Ti–C bonds in the deposited film. The latter trend is attributed to the generation of additional Ti, N, and C active sites at the saturated bonding surface due to plasma ion bombardment; these can react with residual O2, producing more C–O and Ti–O bonds. Smooth, ultra-thin TiN films (<3 nm) are also successfully demonstrated.

TiN film growth on misoriented TiN grains with simultaneous low-energy bombardment: Restructuring leading to epitaxy

We perform large-scale molecular dynamics simulations of TiN deposition at 1200 K on TiN substrates consisting of under-stoichiometric (N/Ti = 0.86) misoriented grains. The energy of incoming Ti atoms is 2 eV and that of incoming N atoms is 10 eV. The simulations show that misoriented grains are reoriented during the early stages of growth, after which the film grows 001 epitaxially and is nearly stoichiometric. The grain reorientation coincides with an increase in film N/Ti ratio. As the grains reorient, additional nitrogen can no longer be accommodated, and the film composition becomes stoichiometric as the overlayer grows epitaxially.

Insight into the structural evolution during TiN film growth via atomic resolution TEM

Although the microstructure evolution during TiN film growth has been extensively studied, how the atomic-resolution structure of the films changes with the deposition conditions remains unclear. Here, a series of TiN films were prepared on silicon substrates at different bias voltages (Vb) by magnetron sputtering. The microstructure and atomic resolution structures of the films were systematically investigated with transmission electron microscopy (TEM) and high resolution TEM (HRTEM), complemented by X-ray photoelectron spectroscopy measurement and density functional theory (DFT) calculations.With increasing the bias voltage, the morphology of columnar grain evolves, and grain size and dislocation density increase, and films become much dense. HRTEM observations reveal that the boundaries between two neighboring grains are dominated by low-angle grain boundaries in the case of floating bias conditions. Numerous twins surprisingly form in the TiN films under certain bias voltage. The initiation of twins in TiN films can be attributed to the reduction of stacking fault energy (SFE) caused by non-stoichiometry to a certain degree, i.e., N/Ti atomic ratio, as validated by theoretical calculations. Moreover, the mechanisms of hardness alterations under different bias-voltages are discussed.

Effect of Additives on the Microstructure of Electroplated Tin Films

Electroplated tin films are important for several technologies such as microelectronics, Li-ion batteries, and corrosion-resistant coatings. In this paper, we demonstrate that the microstructure of tin films can be precisely controlled by addition of certain combinations of organic additives to a methanesulfonic acid based electroplating bath. Tin films are deposited on a copper substrate by varying the concentrations of two such additives, namely, hydroquinone and gelatin. The plating process is characterized by linear sweep voltammetry and insights into the resulting microstructure are obtained using imaging by scanning electron microscopy. It is found that the addition of hydroquinone alone results in non-uniform tin films having significant dendrites and does not affect the hydrogen gas evolution during electroplating. The addition of gelatin alone is found to suppress the evolution of hydrogen gas and affects the film nucleation process that controls its grain morphology, but also creates pinholes in the film and sludge in the bath. A combination of the two additives, however, yields a highly uniform grain structure with little to no dendrite formation and a delayed onset of hydrogen gas evolution, which is highly desirable during the electroplating process. Experiments are carried out that show that the mechanism of tin film nucleation and growth during electroplating is altered in the presence of the additives, where gelatin suppresses the tin nucleation rate (thereby controlling the grain size) as well as the formation of large dendrites; while hydroquinone, acting as an antioxidant, prevents pinholes, creates a uniform film, and avoids sludge formation in the presence of gelatin. This work demonstrates a path to control electroplated tin microstructures by varying bath chemistries and process parameters which will prove highly useful to industry.

MgO/TiN Buffer Layer Structures for Coated Conductor Development on Cu-Based Substrates

A MgO/TiN based multilayer structure suitable as buffer for the development of ReBa <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Cu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7-x</sub> (RE = rare earth, Y)-based coated conductors has been developed. The epitaxial growth of TiN film on cube textured substrate was widely studied in terms of structural and morphological properties. TiN films were epitaxially grown on Ni-W substrates in a wide range of deposition condition. The TiN films are compact and dense with smooth surfaces. An MgO film deposited on the top of the TiN layer reproduces the characteristics of the underlying film. In order to test the TiN/MgO structure, a YBCO film was deposited using a SrTiO3 film as cap layer. A Cu-based cube textured tape was employed as substrate, i.e., Ni-50%at. Cu-0.5%at. W. The YBCO film presents a major c-axis orientation with a sharp out-of-plane distribution. Zero-resistance critical temperature of about 85 K was obtained.

Heteroepitaxial growth of TiN film on MgO (100) by reactive magnetron sputtering.

TiN thin films were deposited on MgO (100) substrates at different substrate temperatures using rf sputtering with Ar/N2 ratio of about 10. At 700°C, the growth rate of TiN was approximately 0.05 μm/h. The structural and electrical properties of TiN thin films were characterized with x-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Hall measurements. For all deposition conditions, XRD results show that the TiN films can be in an epitaxy with MgO with cube-on-cube orientation relationship of (001)TiN // (001)MgO and [100]TiN // [100]MgO. TEM with selected-area electron diffraction pattern verifies the epitaxial growth of the TiN films on MgO. SEM and AFM show that the surface of the TiN film is very smooth with roughness approximately 0.26 nm. The minimum resistivity of the films can be as low as 45 μΩ cm.

Ultra-thin poly-crystalline TiN films grown by HiPIMS on MgO(100) — In-situ resistance study of the initial stage of growth

The growth of ultra-thin TiN films on single-crystalline MgO(100) substrates by high power impulse magnetron sputtering (HiPIMS) was studied for growth temperatures ranging from 35°C to 600°C. X-ray analysis showed that the films had a textured poly-crystalline structure. Films grown by dc magnetron sputtering (dcMS) were epitaxial at the higher growth temperatures. In-situ resistance measurements, during growth, revealed the coalescence thickness and film continuity thickness. The film grown by HiPIMS at room temperature coalesced at 1.2±0.1nm and became structurally continuous at 2.67±0.15nm. At 600°C, the coalescence and continuity thicknesses decreased to 0.56±0.05nm and 0.82±0.05nm, respectively. X-ray reflectivity measurements revealed that the growth rate of the films was roughly constant for all growth temperatures. The film density increased slightly with growth temperature up to 5.3g/cm3 at 600°C and the surface roughness of the films decreased from 1nm to 0.3nm while the growth temperature increased from 35°C to 600°C. Grazing incident X-ray diffraction measurements showed the presence of [111], [200] and [220] crystallites at all growth temperatures. The smallest [200] and [220] grain sizes appeared at 100°C while the [200] grain size increased by increasing the growth temperature.

Growth of Sub-Nanometer Thin Continuous TiN Films by Atomic Layer Deposition

This work reports on the initial growth of atomic layer deposited titanium nitride thin films on SiO2 substrate at temperatures of 350–425°C and process pressures of 2.6–3.2 × 10−2 mbar. We used spectroscopic ellipsometry for in situ monitoring the growth, atomic force microscopy and electrical measurements for further film characterization. We demonstrate that the growth obeys Stranski – Krastanov mode with an initial 2D growth followed by a 3D island formation. The growth of the islands eventually leads to coalescence. We found the 2D–3D transition to be independent of temperature whereas the coalescence of the 3D islands is strongly affected by temperature. The former takes place as the film thickness reaches 0.69 ± 0.1 nm, which is equivalent to 3 monolayers of TiN. The latter occurs at a thickness of 2.5 ± 0.1 nm for 350°C and at a thickness of 3.5 ± 0.1 nm for 425°C.

J124 熱CVD法によるTiN膜成長機構に関する実験的研究(一般講演(2))

J124 熱CVD法によるTiN膜成長機構に関する実験的研究(一般講演(2))

OS1602 イオンビーム支援蒸着法により面外回転体に成膜したTiN薄膜の機械的特性評価(OS16-1 ナノ・マイクロ材料,薄膜の変形と強度,OS-16 ナノ・マイクロの視点からの変形と破壊の力学)

TiN films were deposited on out-of-plane rotating Si(100) substrate by an ion beam assisted deposition technique. The influence of out-of-plane rotation on the film morphology, orientation and mechanical properties was investigated by SEM observation, X-ray diffraction analysis and nano-indentation tests respectively. TN film on rotated substrate showed granular morphology, which is different from that on the fixed substrate showing the columnar morphology. XRD spectra revealed that the out-of-plane rotation promoted the growth of TiN film with (200) preferred orientation. The hardness and elastic modulus of TiN film on rotated substrate was higher than that of TiN film on fixed substrate because of the change of orientation.

Thermal stability of TiN/HfSiON gate stack structures studied by synchrotron-radiation photoemission spectroscopy

We have investigated the thermal stability of TiN/HfSiON gate stack structures using synchrotron-radiation photoemission spectroscopy. Spectral intensities of the Si-oxide components in Si 2p core-level spectra systematically increase with annealing temperature, which strongly depends on the thickness of the TiN metal gate layer. Changes brought by annealing procedures in depth profiles of atomic concentration indicate segregation of Si-atoms at the TiN surface. Furthermore, chemical-state-resolved depth analyses by angle-resolved photoemission spectroscopy suggest formation of TiSix and HfNy components due to chemical bond breaking in the HfSiON layer during TiN film growth. This can be related to the degradation of thermal stability.

A molecular dynamics simulation of TiN film growth on TiN(0 0 1)

The growth of thin TiN films on the TiN(001) surface during reactive sputtering was simulated by molecular dynamics with the modified embedded-atom method potential. TiN3 is found to be the smallest epitaxial island and the film grows via the layer mode. Vacancy concentration in the deposited films decreases with increasing the substrate temperature and kinetic energy of incident atoms, resulting from the enhancement of the thermal diffusion and kinetic energy assisted athermal diffusion. To get the stoichiometric TiN film, the N:Ti flux ratio should be larger than unity and be increased with higher incident energy due to the weak adsorption of atomic N on TiN(001).

Investigating the TiN Film Quality and Growth Behavior for Plasma-enhanced Atomic Layer Deposition Using TiCl$_4$ and N$_2$/H$_2$/Ar Radicals

Investigating the TiN Film Quality and Growth Behavior for Plasma-enhanced Atomic Layer Deposition Using TiCl$_4$ and N$_2$/H$_2$/Ar Radicals

Influence of the magnetic field configuration on the reactive sputter deposition of TiN

AbstractA conventional 2 inch planar, circular magnetron has been designed allowing an in situ variation of the magnetic field configuration, i.e. the distance of the peripheral magnet ring and central magnet cylinder to the target could be varied independently from each other. The development of this kind of magnetron allows us to investigate the influence of the strength and shape of the magnetic field on the growth of TiN films. Such TiN films were deposited on grounded stainless steel substrates by sputtering a pure Ti target in a mixture of Ar and N2. The influence of the N2 flow and the magnetic field configuration on the crystallographic orientation of the deposited films has been investigated. At similar conditions, the influence of the magnetic field configuration and N2 flow on the discharge voltage, deposition rate and the ion flux towards the substrate has been investigated. No clear relationship between the ion‐to‐atom ratio and the crystallographic orientation has been observed.

In-depth Profile Analysis in Metal/high-k Gate Stack Structures Studied by Synchrotron-radiation Photoelectron Spectroscopy

We have investigated the thermal stability of TiN/HfSiON gate stack structures using synchrotron-radiation photoemission spectroscopy. Spectral intensities of the Si-oxide components in Si 2p core-level spectra systematically increase with annealing temperature, which strongly depends on thickness of the TiN metal gate layer. Changes brought by annealing procedures in in-depth profiles indicate segregation of Si atoms at the TiN surface. Furthermore, chemical-states-resolved in-depth analyses by angle-resolved photoemission spectroscopy suggest formation of TiSix and HfNy components, due to chemical bond breaking in the HfSiON layer during TiN film growth. This can be related to the degradation of thermal stability.