Modified Salicide Process With Via Dry Etch Stop
Original Publication Date: 1984-Dec-01
Included in the Prior Art Database: 2005-Feb-06
The current drive toward increased circuit density and chip area reduction results in severe topological variations leading to 90Œ walls between gate electrodes and adjacent diffusions. The most current "salicide" approach utilizes E-beam deposited Ti to react with open junctions and gate electrodes. A modified salicide process is described herein that prevents overetching of shallower vias until all the vias are opened. The process sequence is as follows: 1. Deposit, by either E-beam or chemical vapor deposition (CVD), the Ti, followed by the deposition of 200 to 300 of cobalt (Co). 2. Perform the salicide diffusion within the temperature range of 600 to 700 C. This will yield layered silicides without significant interdiffusion of the layered metals over the oxide zones.