Effect of Poly(vinylpyrrolidone) As a Stress-Relaxing Additive in Fabrication of PbZrxTi1-xO3 Thin Films Using Sol-Gel Route

We investigated how poly(vinylpyrrolidone) (PVP) suppresses crack generation during fabrication. It was confirmed that PVP plays the role of a stress-relaxing agent by in situ stress development measurement at temperatures from 200 to 300 degrees C. We found that PVP in the film was removed in two steps and that the residual PVP-decomposition product can be the cause of void generation. It was revealed that Young's modulus of the lead zirconate titanate (PZT) film prepared from PZT-PVP-sol was lower at temperatures from 300 degrees C to less than that from 400 degrees C than from PZT-sol during fabrication despite the fact that the each values at 450 degrees C are almost the same. It implies that PVP suppress crack formation by degrading Young's modulus of the film before crystallization. We obtained a 2-mu m-thick PZT film with only 10 coatings and its electrical properties is equivalent to previously reported values obtained using the sol-gel route. (c) 2013 The Japan Society of Applied Physics