We report on the characteristics of rapid-thermal-annealed LiNi1-xCoxO2 cathode films for all-solid-state thin film microbatteries (TFBs). Scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy and Auger electron spectroscopy results show that the surface oxide layer formed on the as-deposited LiNi1-xCoxO2 film is completely removed by a rapid thermal annealing process. All-solid-state TFBs consisting of Li/LiPON/LiNi1-xCoxO2/Pt/MgO/Si exhibit stable cyclibility and a high specific discharge capacity of 60.2 muAh/cm(2) mum. It is concluded that the LiyNi1-xCoxO2 cathode could represent a promising candidate for a cathode film in TFBs. (C) 2003 Elsevier B.V. All rights reserved.