Low-Temperature Titanium Salicide Process
Original Publication Date: 1986-Feb-01
Included in the Prior Art Database: 2005-Mar-08
The conventional process for Ti self-aligned silicide involves two-step annealing at 675ŒC and 800ŒC. The unwanted Ti is etched after the 675ŒC anneal. Since the annealing is done in N atmosphere, approximately 1/3 of Ti at the top of Ti film is converted to TiN and the remaining 2/3 is converted to TiSi . In this publication an improved process is described which employs a lower annealing temperature (675ŒC) to obtain the similar low resistivity. A thin capping layer of amorphous Si in the thickness range of 200 to 300 ˜ is deposited in situ by sputtering (or by evaporation) after deposition of Ti. The cap protects the Ti film during annealing, thus producing the desired TiSi film at a lower temperature.