W-CMP for sub-micron inverse metallisation

Chemical Mechanical Polishing (CMP) of tungsten for an inverse metallisation scheme is investigated. The influence of CMP parameters on removal rate and uniformity is studied. The main effects on the removal rate are the applied pressure and the rotation rate of the polishing pad. To the first order Preston's equation is obeyed. The uniformity is best with equal rpm of pad and wafer and with perforated pads. Also, pattern density effects of CMP of W/PETEOS are investigated. Dishing increased at larger W-linewidth. Oxide erosion increased at larger pattern density and smaller W-linewidth. Electrical measurements on submicron (0.4 and 0.5 ¿m) test structures yielded good CMP results

The effect of thermal annealing on the adherence of Al2O3-films deposited by low-pressure, metal-organic, chemical-vapor deposition on AISI 304

Thin alumina films, deposited at 280°C by low-pressure, metal-organic, chemical-vapor deposition on stainless steel, type AISI 304, were annealed at 0.17 kPa in a nitrogen atmosphere for 2,4, and 17 hr at 600, 700, and 800°C. The effect of the annealing process on the adhesion of the thin alumina films was studied using a scanning-scratch tester, type SST-101, developed by Shimadzu. The best mechanical properties were obtained with unannealed samples. After thermal annealing the critical load decreased, proportional to annealing time and/or temperature. This effect was probably due to the presence of a high thermal stress and to preferential segregation of sulfur near the oxidealloy interface