Oxide-Nitride Storage Dielectric Formation in a Single-Furnace Process for Trench DRAM

Abstract

Abstract-A simplified and integrated technique has been proposed to form an oxide/nitride storage dielectric in a single-furnace process by low-pressure oxidation and nitride film deposition with an extra N 2 O treatment for the trench dynamic random access memory (DRAM). Compared to the conventional nitride/oxide dielectric, this newly developed dielectric enjoys cellcapacitance-enhancement factor as high as 12.5% without degrading the leakage current and electron-trapping property. From the reliability test, the qualification for the DRAM application is also proven by the dielectric lifetime longer than 10-years. Most importantly, this technique can reduce the production cycle time without an additional equipment investment, which is essential in the cost-competitive DRAM arena.Index Terms-N 2 O treatment, oxide/nitride (ON) stack, singlefurnace process, storage dielectric, trench dynamic random access memory (DRAM).

Augmented Cell Performance of NO-Based Storage Dielectric by N<formula formulatype="inline"><tex>$_2$ </tex></formula>O-Treated Nitride Film for Trench DRAM

“…Nevertheless, the related process development can be rarely found. In our previous study, possible methods including oxide with NH 3 /N 2 O treatment [6], oxide formed with wet N 2 O [7], and low-pressure oxide treated by N 2 O [8] have been proposed in order to boost the cell capacitance with acceptable tunneling leakage current by transforming conventional pure oxide into oxynitride in which a moderately higher dielectric constant can be achieved. These techniques have been proved to be highly suitable to be integrated into current process with prominent cell performance enhancement.…”