We investigate the crosslinking process in ion irradiated AZ 1350J™ photoresist. The films were deposited on clean silicon wafers and irradiated with 380 keV He ions in the fluence range of 1013 to 1016 He.cm-2, corresponding to average deposited energy densities from 0.02 to 20 eV. Å-3.respectively. Nanoindentation, Raman spectroscopy as well as gel content and density measurements have been used to determine mechanical and structural properties of the irradiated films. The results show that the irradiation induces crosslinking of the polymeric chains but also produces carbonization of the films. For deposited energy densities up to 2 eV.Å-3. the crosslinking process is predominant and is mainly responsible for the increase of hardness and Young's modulus by respectively 5 and 2 times in relation to the values of the pristine film and for the gel content of 90%. For deposited energy densities larger than 2 eV.Å-3, the photoresist film is progressively transformed into an amorphous carbon layer as is shown by the Raman results, and also by the increase of the density at a deposited energy of 20 eV.Å-3.

We investigate the morphological features of sputter eroded surfaces, demonstrating that while at short times ripple formation is described by the linear theory, after a characteristic time the nonlinear terms determine the surface morphology. We also show that the morphological transitions induced by the nonlinear effects can be detected by monitoring the surface width and the erosion velocity.

We report on the simulation of the growth and subsequent krypton ion polishing of thin molybdenum films, required for extreme ultraviolet multilayer mirror fabrication. We have used a comprehensive Molecular Dynamics (MD) code, principally enabling a simulation of the deposition, ion bombardment and annealing processes. Ion energies used are in the sub-keV range, and the ion angle of incidence is varied between 30 and 60 degrees off-normal.

The effects of ion polishing on the surface roughness are discussed, as well as the increase in (surface) atom mobility. We also report data on sputtering yields, ion penetration depths, trapping, energy transfer and krypton implantation and saturation.

The results are compared with TRIM results, and the relevance of MD and TRIM simulations for specific purposes is discussed. Also, the effects of short-time, high-temperature annealing of an amorphous film are investigated.

Optimization of the surface topography, especially in high-temperature superconductors (HTS) and silicon carbide is crucial for device processing. Surface smoothing in these materials was investigated using Gas Cluster Ion Beams (GCIB) capable of delivering cluster ions of ≥ 2000 Ar atoms with energies of up to 30keV. Examination of the surface topography after cluster-ion irradiation was done using cross-sectional transmission electron microscopy (TEM) and atomic force microscopy (AFM). The results indicate that typical as-deposited YBCO films on MgO substrates have an average roughness of the order of 40 nm, and interpeak distance between 300–600 nm. Application of GCIB to the surface planarization reduces the roughness to only 10 nm. Also power handling and microwave surface resistance of the YBCO film and its relationship to surface smoothness are reported. Similar observations using bulk SiC are discussed.