High pressure oxidation induced stress in submicron trench structures

The maximum stress induced by high pressure oxidation (wet and dry) in the vertical bird's beak of submicron trench structures has been investigated experimentally. The oxidation induced stress was measured via wafer bow on wafers that were patterned with a special trench mask featuring a pattern factor of 50%. For wet high pressure oxidations above 850°C, the stress drops from 2×1010 dyne/cm2 at 850°C to a value below 1×109 dyne/cm2 at 1000°C. At oxidation temperatures between 700 and 900°C, dry pressure oxidations show lower stress than wet oxidations. © 1996 American Institute of Physics.