Influence of the calcium phosphate content of the target on the phase composition and deposition rate of sputtered films

Calcium phosphate was coated from tetracalcium phosphate (TTCP), hydroxyapatite (HA), β-tricalcium phosphate (TCP), β-calcium pyrophosphate (CPP), and β-calcium metaphosphate (CMP) powder targets using radio frequency magnetron sputtering. The composition of the crystal phase of the coated films was changed, depending on the target materials, and the Ca/P molar ratios of the films varied from 0.74 to 2.54, increasing with the Ca/P molar ratio of the target. The solubility of the target, determined using a microwave-induced plasma-mass spectrometer was: TTCP ≈ β-CMP > β-TCP > β-CPP > HA, and the deposition rate from each target showed a similar order to the solubility: TTCP ≈ β-CMP > β-TCP > β-CPP ≈ HA.