The data provided here has been used in the preperation of figures for the following manuscript:

Z. Golrokhi, S. Chalker, C.J. Sutcliffe and R.J. Potter, 'Self limiting atomic layer deposition of conformal nano-structured silver films', submitted to Applied Surface Science (2015).



2 Experimental procedure

2.1 ALD growth experiments 
Silver films were deposited on polished virgin test grade Si(100) (Compart Technology Ltd) by thermal ALD using a customised Aixtron AIX 200FE reactor. A 0.1 M solution of ((hfac)Ag(1,5-COD))(supplied by SAFC Hitech Ltd) in anhydrous toluene (Sigma Aldrich) was used as the silver precursor. Once in solution, the silver precursor is moisture and light sensitive and hence solutions were carefully prepared in a nitrogen glove box and were then stored under inert gas in the dark. The silver precursor was introduced into the reactor at a rate of 17.5 µl/s by direct liquid injection along with 200 sccm of argon (99.999%, BOC) carrier gas. The precursor solution was volatilised using a Jipelec vaporizer set at 130 degC (it is important to note that the precursor vapour does not actually reach 130 degC in the vaporizer due to the flow of carrier gas). Propan-1-ol (HPLC grade from Fisher Scientific) was used as a co-reactant and was introduced into the reactor as a vapour, via a Swagelok ALD valve, using a conventional vapour-draw source held at room temperature (~20 degC). The ALD cycle was defined by sequential pulses of the two reactants separated by inert gas purges (Argon) to prevent gas phase reactions. The effects of growth temperature silver precursor dose, co-reactant dose and number of ALD cycles were all investigated. Growth was carried out at a nominal reactor pressure of 5 mbar. Samples were allowed to ‘soak’ at the set-point temperature for 20 minutes prior to deposition to ensure that they reached thermal equilibrium with the graphite susceptor (a standard deviation of ±0.2 degC was recorded in the temperature throughout the deposition period).  

2.2 In-situ measurements
In-situ measurements of the ALD process kinetics at 125 degC with 6 s long saturative precursor doses and extended (15 s) purge steps were carried out using a QCM system. The system utilised a Maxtek TM-400 monitor, a SO-100 oscillator, a custom built low thermal mass crystal holder and a high temperature Y-11° cut GaPO¬4 crystal optimised for 0-460 degC (R20 crystal, Tangidyne Corp). The crystal holder was placed at the front of the reactor’s graphite heater and the temperature of the heater was adjusted until the crystal itself was 125 degC (as measured by a low thermal-mass thermocouple).  The weight gain per unit area was calculated using the Sauerbrey equation with a crystal density and shear modulus of 3.57 g/cm^3 and 2.147 g/cm.s^2, respectively.

2.3 Physico-chemical characterisation
Film deposition rate was estimated gravimetrically by measuring the mass change of 30 × 30 mm Si(100) samples after deposition using a Mettler Toledo XS205-DU analytical micro balance. Nominal film thickness was estimated from the gravimetric analysis by assuming a bulk silver density of 10.5 g/cm^3. Film microstructure and topography was analysed using x-ray diffraction (XRD), and scanning electron microscopy (SEM), while the chemical composition was investigated using energy-dispersive x-ray spectroscopy (EDX) and x-ray photoelectron spectroscopy (XPS). SEM image analysis was carried out using macro particle size analyzer (PSA_r12) in Image J sampling 1 µm^2 areas. Each sample was analysed by randomly sampling at least four areas to ensure that the resulting data was representative of the whole. Manual measurements of particle sizes was carried out to verify the ImageJ analysis and also to measure irregular shaped nano-particles. XRD was carried out using a Bragg-Brentano diffractometer (Rigaku miniflex) with a Cu Ka1 source (? = 1.5405 Å). SEM was carried out using a JEOL JSM-7001F FEG-SEM equipped with an Oxford Instruments INCA x-act-51-ADD0001 detector for EDX measurements.  XPS measurements were carried out using a FISONS VG Escalab MKII with an Al Ka x-ray source (1486.6 eV).  

2.4 Porous foam structures characterisation
To assess the conformity of the ALD coating onto complex three dimensional surfaces, test structures in the form of porous titanium foam were fabricated by selective laser melting (SLM) using the randomised foams as described in reference [L. Mullen et al., J. Biomed. Mater. Res. Part B Appl. Biomater. 92(1) (2010) 178-188.]. ‘Split cube’ samples with a porosity of ~65% were designed to enable SEM of internal surfaces within the three dimensional structures. Each sample was made up of two 2.5 × 5 × 5 mm foam blocks tightly wired together to form 5 × 5 × 5 mm cubes. The samples were coated using 500 cycles of ALD with either 2 s or 4 s doses of precursor, while keeping the co-reactant dose and purge times fixed at 4 s and 9 s respectively.  Following ALD, the two halves of the cubes were separated and SEM was used to look at the coating on the internal surfaces. 



Data files: 

FILE TYPES: Numerical data is provided as .CSV files. 
FILE NAMING: File names are directly related to the figure numbers used in the manuscript.
DATA HEADINGS: The first row of each column in the .CSV files contains a clear description of the data within the column together with units in brackets.