PREPARATION OF CUTI-CN(3)TI COMPOUND ALLOY-FILMS AND THEIR APPLICATIONS AS DIFFUSION BARRIER IN CU CUTI-CU3TI/TIN/SI MULTILAYERED CONTACT SYSTEM/

The CuTi2 intermediate layer in a Cu/CuTi2/Ti/Si multilayered contact system disappears when heat-treated at a temperature higher than 500 d egrees C. Thus, to improve the thermal stability of a Cu/CuTi2/Ti/Si m ultilayered contact system, it is necessary to replace the CuTi2 layer with other Cu-Ti compounds that are thermally stable at temperatures higher than 500 degrees C. Among various Cu-Ti compounds, Cu3Ti is the most stable compound formed by heat-treating the Cu/Ti bilayered syst em. However, since it is difficult to form a monolithic layer of Cu3Ti intermetallic compound, Cu-Ti alloy systems which contain Cu,Ti and c an be formed at relatively low temperature were investigated. The CuTi -Cu3Ti compound alloy films were formed when the Cu/Ti bilayers were h eat treated at 350 degrees C for four hours. Thus, the thermal stabili ty of a Cu/CuTi-Cu3Ti/TiN/Si contact system was investigated. The expe rimental results indicate that the top layer of Cu can be preserved ev en when heated at 600 degrees C and the interdiffusion between Cu and Si can be minimized.