| 摘要 |
PROBLEM TO BE SOLVED: To form a composite TiN film having an improved step coverage, low film stress and suitable for for a plugging of small dimensions compared to the case by a standard TiN process. SOLUTION: The method for forming a titanium nitride (TiN) layer uses the reaction between ammonia (NH3) and titanium tetrachloride (TiCl4). In one embodiment, a TiN layer is deposited by using the temp. of about 500 deg.C, the pressure of about 2 Torr and the NH3:TiCl4 ratio of about 8.5. In an another embodiment, a composite TiN layer is formed by alternately depositing plural TiN layers with different thickness by using the process condition having different NH3:TiCl4 ratios. In one suitable embodiment, a TiN layer of about <20 angstrom is formed at the NH3:TiCl4 ratio of about 85, and after that, a thicker TiN layer is deposited at the NH3:TiCl4 ratio of about 8.5. By repeating the deposition of alternate layers by using two different process conditions, a composite TiN layer is formed.
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