AVS 51st International Symposium
    Electronic Materials and Processing Tuesday Sessions
       Session EM-TuM

Paper EM-TuM10
Influence of Interactions Between Ta-N Films and Low Dielectric Constant Materials on the Stability of Copper Interconnection

Tuesday, November 16, 2004, 11:20 am, Room 304B

Session: Contacts and Metallization
Presenter: J.-S. Chen, National Cheng Kung University, Taiwan
Authors: C.-C. Chang, National Cheng Kung University, Taiwan
S.-K. JangJian, Taiwan Semiconductor Manufacturing Company, Taiwan
J.-S. Chen, National Cheng Kung University, Taiwan
Correspondent: Click to Email
Low dielectric constant (low-k) materials integration with copper metallization has been adopted widely in integrated circuits. In this work, properties of copper layers in the Cu/Ta-N/Ta/low-k materials/ structures were explored, where Ta-N layers are as-deposited amorphous TaN@sub x@ (x~0.5) or polycrystalline TaN films and low-k materials include fluorinated silicate glass (FSG) and organosilicate glass (OSG), respectively. The samples in the Cu/Ta-N/Ta/low-k materials structures were annealed in vacuum at 400°C for 30 minutes or an hour. Thermal interactions between Cu and Ta-N films or Ta-N layers and low-k materials were investigated by using sheet resistance measurement, X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectrometry, and transmission electron microscopy. As the thickness of Ta-N films decreases from 50 nm to 10 nm, the preferred orientation of (111)@sub Cu@ will be improved significantly in the Cu/TaN@sub x@ systems after annealing. On the other hand, as the thickness of the Ta-N films decreases to 5 nm, surface morphologies of these as-deposited and annealed copper layers are different obviously from the others with thicker Ta-N barriers. It is attributed to the interfacial reactions between the Ta-N layers and low-k materials and the properties of the ultra-thin Ta-N films itself. All of these effects would be discussed in this study.