Since TiSi2 is perhaps the most attractive candidate for the self-aligned silicide technology, it is important to understand the high temperature process limitations of this material. Thin TiSi2 films are formed on single-crystal silicon, or polysilicon, and, when annealed in He or N2 at temperatures of 900°C or higher, result in degradation of surface morphology and a drastic increase in sheet resistance. Eventually, isolated TiSi2 agglomerates are formed on the surface in case of He annealing. In the case of nitrogen annealing, they are covered with TiN. Shallow junctions with a thin self-aligned TiSi2 layer formed on top were electrically stable up to 900°C. Heat-treatment beyond this temperature caused both the junction leakage and the contact resistance to increase. In addition to agglomeration, when thin TiSi2 films were formed on polysilicon, mixing of TiSi2 into polysilicon at temperatures beyond 850°C was observed. In the case of MOS devices, this degrades gate integrity. © 1986, The Electrochemical Society, Inc. All rights reserved.