Newly devleoped low-k and low-stress fluorinated silicon oxide utilizing temperature-difference liquid-phase deposition technology

摘要

To meet the requirements of low-K and low-stress intermetal dielectric (IMD0 for future ULSI devices, a novel temeprature-difference liquid-phase deposition (TD-LPD) method is proposed. The deposition solution of supersaturated silicic acid with high concentration of fluorine can be achieved by raising deposition temperature larger than 15 deg from dissolution temperature (0 deg). Because fluorine atoms can esily be incorporated with the technique. TD-LPD fluorine-doped SiO_2(FSG) exhibits low-K (rpprox 3.4) and low-stress (approx 40 MPa) property. In this paper, to study the interaction between TD-LPD FSG and moisture, the FSG is annealed and moisture stressed repeatedly as in a real process. Since K is sensitive to moisture absorption, and teh stress is sensitive to the dehydration reaction between Si-OH's, the both are monitored as indices. A feasible mechanism is proposed to explain the variation in K/stress during annealing and boiling cycles.