Improved uniformity for thin oxides when using wet thermal oxidation

Wet thermal oxidation is an accepted process for generating thick oxide films but is not commonly used for thin oxide films due to issues with film uniformity. For high wafer loading and oxide thicknesses at and below 1000Å, dry oxidation has been the process of choice. A new wet oxidation method using high flow rates of steam and oxygen has now been shown to achieve uniformity better than 2% load to load and reduce oxidation time by 87%. These results were achieved in tests on large wafers (300 mm), demonstrating improved economies within uniformity tolerances.