Sudha Rathi

Resist Poisoning-Free Advanced PECVD-Based Anti-Reflective Coating (ARC) for 90nm Technology and Beyond

A nitrogen-free (N-free) dielectric anti-reflective coating (DARC®) was cost-effectively developed in a plasma-enhanced chemical vapor deposition (PECVD) reactor to eliminate the 193nm resist poisoning interaction caused when N 2 O is used as a precursor [1]. Although it was found that even a N-free ARC could poison sensitive 193nm resists with –OH radicals [2], which either exist inherently in the ARC or result from H 2 O absorption by the ARC surface, the current investigation has revealed that it was possible to minimize resist poisoning. Our investigation showed that compressive film stress directly correlates to H 2 O resistance. Therefore, it was possible to greatly improve the ARC resistance to H 2 O absorption by creating and maintaining a process regime that makes the ARC film dense. The dense ARC film demonstrated promising lithography performance with minimal resist poisoning as well as excellent shelf life and O 2 -ashing resistance. This paper explores the N-free DARC material, its development, lithographic integration results and implementation in a production environment to eliminate 193nm resist poisoning.

BLO/spl kappa//sup TM/-a low-/spl kappa/ dielectric barrier/etch stop film for copper damascene applications

A low-/spl kappa/ dielectric barrier/etch stop film has been developed for use in copper damascene processes. The film is deposited using Dow Corning/sup R/ organosilicon gas as a precursor in a single-wafer PECVD chamber, and has a lower dielectric constant (/spl les/5) compared to the SiC film (>7) generated by SiH/sub 4/ and CH/sub 4/ and plasma silicon nitrides (>7). This film is amorphous and composed of silicon, carbon and hydrogen (a-SiC:H). The film characterization, including physical, electrical, copper diffusion barrier properties, and etch selectivity demonstrated that this film is a good barrier/etch stop for low-/spl kappa/ copper damascene applications. Due to its low dielectric constant, low effective /spl kappa/ values can be achieved in damascene devices. This film has been named BLO/spl kappa//sup TM/ (barrier low /spl kappa/) (Pai and Ting, 1989).