Appeal No. 2005-1220 Application No. 09/270,606 Page 7 blanket polishing rate.3 Concerning those claimed polishing rates, we note that each of those claimed rate terms employ a term of degree (“substantially” or “approximating”), which terms thus encompass a range of polishing (silicon dioxide layer high and low structure area removal) rates. In this regard, appellant’s specification furnishes graphs and descriptions thereof that reasonably make clear those claimed rate ranges encompass rates significantly different than either a zero removal rate or a blanket removal rate, respectively. For example, at page 5, line 2 through page 7, line 13, appellant’s specification provides that (underlining supplied): If polishing using ceria slurry is carried out for a sufficiently long time, two important results occur: First, when the substrate surface becomes substantially planarized, polishing characteristics revert back to more conventional behavior. Second, if silicon, polysilicon, or silicon nitride underlie the polished layer of silicon dioxide, they tend to act as a polish stop. These results are illustrated in FIGS. 6a-6d, which depict polishing characteristics for feature size scales corresponding to FIGS. 3 and 5. Long term ceria polishing characteristics are illustrated generally at 60. A high area rate 62 approximates blanket rate 20 over time, while a low area rate 64 is close to zero. Convergence points 66 are reached in some instances, with a converged rate 68 being shown for those instances. Where an appropriate underlying material is present, a polish stop rate 70 is shown. 3 A blanket polishing rate is defined in appellant’s specification as a removal rate that is obtained (measured) on an unpatterned waiver. See page 2, line 23 of appellant’s specification.Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 NextLast modified: November 3, 2007