Using reactive radio frequency magnetron sputtering, TiN/ZrN multilayers were deposited on Si (111) substrates at 550 degrees C. The multilayers were annealed at different temperatures ranging from 500 to 1100 degrees C in air. The variation of the annealed multilayers has been investigated by X-ray diffraction and transmission electron microscopy. A layer-by-layer oxidation behavior is found in the multilayers annealed at temperatures below 900 degrees C. The oxidation mechanism of multilayers is discussed in the paper. (C) 2007 Elsevier B.V. All rights reserved.