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 inve stigated experimentally. The oxidation induced stress was measured via wafer bow on wafers that were patterned with a special trench mask fe aturing a pattern factor of 50%. For wet high pressure oxidations abov e 850 degrees C, the stress drops from 2x10(10) dyne/cm(2) at 850 degr ees C to a value below 1x10(9) dyne/cm(2) at 1000 degrees C. At oxidat ion temperatures between 700 and 900 degrees C, dry pressure oxidation s show lower stress than wet oxidations. (C) 1996 American Institute o f Physics.