Yung-Chin Yang

Characterization of multilayered Ti/TiN films grown by chemical vapor deposition

The resistivity of multilayered Ti/TiN films grown by chemical vapor deposition can be reduced from 240 μΩ cm (standard sample) to 120 μΩ cm with NH 3 plasma post-treatment for 300 s. Increasing the number of multilayered Ti/TiN films of reduced thickness and a plasma post-treatment technique contributed to reducing the resistivity of TiN films effectively. Smooth multilayered Ti/TiN films were observed by XTEM image. The content of chlorine in the multilayered Ti/TiN film was 1.6 at.%. Therefore, corrosion in the subsequent Al film should be minimized. SIMS depth profiles of the multilayered Ti/TiN sample showed that Ti atom distribution is fairly uniform. The result is in agreement with the observation of XTEM and the measurement of AES depth profiles. The resistivity of multlayered Ti/TiN films can be further reduced to 75 μΩ cm with an in situ NH 3 plasma post-treatment (500 W) for 300 s followed by RTA at 900°C for 60 s. Therefore, low resistivity (<100 μΩ cm) and low Cl concentration (<2 at.%) CVD TiN films can be achieved by a combination of forming a multilayered Ti/TiN structure, and using NH 3 plasma post-treatment and RTA.