Amorphous Si and Co/Ti bilayers were sequentially evaporated onto 5- 10nm thick CoSi 2 and rapidly thermal-annealed(RTA) to form Co-polycide electrodes. Then, MOS capacitors were fabricated by doping poly-Si using SADS method. The C-V and leakage-current characteristics of the capacitors depending upon the RTA conditions were measured to study the effects of thermal stability of CoSi 2 and dopant redistribution on electrical properties of Co -polycide gates. Capacitors RTAed at 700 ? C for 60-80 sec., showed excellent C-V and leakage-current characteristics due to degenate doping of poly-Si layers. But for longer time or at higher temperature, their electrical properties were degraeded due to CoSi 2 decomposition and subsequent Co diffusion. When making Co-polycide gate electrodes by SADS, not only degenerate doping of poly-Si layer. but also suppression of have been shown to be very critical.