The use of rapid thermal processing to control dopant redistribution during formation of tantalum and molybdenum silicide/n+polysilicon bilayers

The successful use of rapid thermal processing (RTP) to form Ta- and Mo-polycide structures is described. Samples were annealed by exposure to the blackbody radiation of a resistively-heated graphite heater in vacuum. Rapid redistribution of phosphorus in the bilayer structure is observed during the sintering process. Long-time high-temperature anneals can result in significant loss of dopant from the polycide structure. Data is presented to show that RTP parameters can be optimized to produce highly-conductive polycide structures with minimal dopant loss from the poly-Si layer, which is not possible for furnace-annealed samples.