A comparative study of copper drift diffusion in plasma deposited a-SiC:H and silicon nitride

✍ Scribed by F. Lanckmans; W.D. Gray; B. Brijs; K. Maex

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 204 KB
• Volume: 55
• Category: Article
• ISSN: 0167-9317
• DOI: 10.1016/s0167-9317(00)00464-0

✦ Synopsis

Advanced back-end processing requires the integration of low-k dielectrics and Cu. To successfully integrate these materials, plasma deposited films for hard mask use with good resistance to wet chemicals, aggressive etch and chemical mechanical polishing are essential. As a solution to providing quality hard masks, a process has been developed for deposition of a trimethylsilane-based a-SiC:H. Depending on the deposition temperature, the dielectric constant can be varied between 4.2 and 4.9. The Cu drift rate in two different types of a-SiC:H and Si N is quantified using bias temperature 3 4 stressing in combination with high frequency capacitance / voltage (C /V ) measurements on capacitor structures. The drift diffusion experiments indicate that a-SiC:H is a potential candidate to replace the high dielectric constant Si N as a Cu 3 4 diffusion barrier and hard mask. C /V measurements and elastic recoil detection are performed to show the thermal stability of the a-SiC:H up to 5008C.