Mothod for manufacturing semiconductor device by annealing rapidly tungsten contact plug under oxygen atmosphere and reducing the RTO pulg under hydrogen atmosphere

摘要

When depositing tungsten in the contact hole, the grain of tungsten proceeds in three directions, resulting in seam and other localized steps at the triple point. If a contact plug is present in the contact plug, the tungsten deteriorates and the yield decreases. In order to improve the local level difference, when the tungsten is heated to a high temperature in an oxygen atmosphere, the volume is expanded to 2 to 3 times. The tungsten contact plug is subjected to rapid thermal annealing (RTA) by heating or plasma treatment in a high-temperature oxygen atmosphere, and the tungsten which has been bulk-expanded on the surface of the interlayer insulating film is removed by a CMP process. In order to improve the contact resistance in the oxidation process of tungsten, rapid thermal oxidation (RTO) and buffing-polished tungsten contact plugs are subjected to rapid thermal reduction (RTH) in a hydrogen gas atmosphere, and tungsten The oxide (W _x O _y ) is converted to pure tungsten (W).;Tungsten, 씸, RTA, buffing, reduction