High density plasma deposited phosphosilicate glass as pre-metal dielectrics for advanced self-aligned contacts in sub 0.25 mu m device technology

High density plasma deposited phosphosilicate glass (PSG) films were evalua ted for an application as pre-metal gap-fill dielectric material. A high de position rate (similar to 600 nm/min) PSG film with 9 at. % of P and a depo sition-to-etch ratio of 5:1 was developed for a void-free gap fill down to 0.04 mu m. Chemical-mechanical polish, reactive ion etch, and defect test o f the PSG film have revealed that as-deposited PSG has performed similar to the annealed one, and PSG has an excellent him stability. A significant de vice yield improvement was obtained using this 9 at. % PSG process. (C) 199 9 American Vacuum Society. [S0734-211X(99)05605-X].