Method of fabricating a thin and structurally-undefective dielectric structure for a storage capacitor in dynamic random-access memory

[[abstract]]A semiconductor fabrication method is provided for the fabrication of a dielectric structure for a storage capacitor in dynamic random-access memory (DRAM). In particular, the resultant dielectric structure can be fabricated thinner and more structurally-undefective than the prior art. By the method, a first nitridation process is performed to form a dielectric layer over a bottom electrode. Next, a layer of silicon nitride is formed over the dielectric layer. This silicon nitride layer would be typically formed with an undesired rugged surface with many punctures. To eliminate this structural defect, a second nitridation process is performed on the silicon nitride layer. The resultant silicon nitride layer and the dielectric layer in combination constitute an ON structure serving as the intended dielectric structure. Alternatively, an oxide layer can be further formed over the silicon nitride layer to constitute an ONO structure serving as the intended dielectric structure. The second nitridation process can be carried out either through a rapid thermal treatment process with the use of nitrogen, ammonia, or a mixture of nitrogen and ammonia; or alternatively through a nitrogen plasma treatment process.[[fileno]]2020309060020[[department]]材料科學工程學