Electron- and Ion Beam-Assisted Deposition EBAD, IBAD

Electron- and Ion Beam-Assisted Deposition (EBAD, IBAD) 

Hung and Yongyi (2010) reviewed the application of focused ion beam (FIB) sputtering for micro/nano fabrication. Although less relevant for discussion of bioceramic coatings, treatment of basic principles of FIB, and evaluation of empirical and fundamental models for sputtering yield, material removal rate and surface roughness were presented and compared. Fabrication of various micro- and nanostructures was discussed. 

Cui and Li (1999) addressed the problem of temperature sensitivity of IBAD of ACPs and their subsequent crystallisation forming hydroxyapatite. Post-depositional annealing temperatures were decreased to 400 °C. The crystallisation of calcium phosphate coating is a hydroxyl ion diffusion-controlled process, thought to be the mechanism responsible for the decrease of the crystallisation temperature. The detailed study of the crystallisation process of calcium phosphate coatings shows that the crystallinity of the hydroxyapatite coating can be well controlled by adjusting the post-heat-treatment time. 

Kim etal. (1998) deposited about 0.5 pm thick homogeneous and dense hydroxyapatite coatings by IBAD on a-alumina substrates. The ACP layer crystallised to dense HAp after annealing at 500 °C for 2 h and immersion in deionised water for 72 h at room temperature. The adhesive strength between HAp and the a-alumina substrate was measured by a scratch test and the critical load was found to be around 43 N (4300 gf). The ion-beam sputtered coatings were used as control samples. The adhesion was found to be worse for IBSD than for IBAD. Indeed, using IBSD the critical load of HAp on alumina was measured to be only about 39 N (3900 gf). 

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