MECHANISMS OF X-RAY RADIATION-INDUCED DAMAGE IN (BA,SR)TIO3 CAPACITORS

X-ray radiation-induced damage has been investigated for (Ba, Sr)TiO3 [BST] capacitors prepared by chemical vapor deposition (CVD). Synchrot ron radiation (SR) X-ray irradiation with similar to 1.65 keV photons was conducted directly on the Pt/BST/Pt and Ru/BST/Ru capacitors at di fferent dose levels of 10, 50 and 130 mJ/cm(2) measurements of the lea kage current versus applied voltage showed an increase in the leakage current caused by X-ray irradiation. The degree of degradation in the current leakage tended to depend both on the X-ray dose and on the ini tial film properties. However, upon a subsequent annealing at 400 degr ees C in an O-2 ambient, the degradation was seen to be completely rem oved and the initial properties were recovered. The degradation and it s observed recovery are ascribed to the creation and annihilation of t rapped positive charges in BST films, induced by charge damage.