Keith Doran Weeks

TiCl4 as a Precursor in the TiN Deposition by ALD and PEALD

This study explores TiN film deposition using the plasma enhanced atomic layer deposition (PEALD) technique, comparing the results of PEALD-TiN with the previous results of ALD-TiN and ALD-TiN with in situ reduction. Eachof the studies used TiCl 4 precursor as the titanium source. The ALD-TiN study used ammonia as the reducing agent. Nitrogen and hydrogen gases are not reactive in the ALD-TiN deposition, but they were successfully used in PEALD-TiN. This study shows that the concept of self-saturating reaction in ALD differs from PEALD. Although the growth rate saturates as a function of pulse lengths, the number of active surface sites and the film composition can be changed by the plasma pulsing parameters. In all deposition techniques the TiN films exhibit excellent film properties including low resistivity, low impurity concentration, and high-density films. PEALD provides significant advantages if the deposition temperature is lower than 350°C.