Highly Reliable Dynamic Random Access Memory Technology for Application Specific Memory with Dual Nitrogen Concentration Gate Oxynitrides Using Selective Nitrogen Implantation

A polymetal dual gate dynamic random access memory (DRAM) for application specific memory (ASM) with dual nitrogen concentrated oxynitrides was developed for the first time. This technology uses selective nitrogen implantation performed just after gate oxidation. The nitrogen concentration of p-type metal oxide semiconductor (PMOS) in gate dielectric combined with nitrogen implantation and NO (nitric oxide) annealing is sufficiently high to suppress boron penetration, whereas that of the cell array transistor (cell-Tr) and n-type metal oxide semiconductor (NMOS) is sufficiently low to maintain the threshold voltage (Vth) without increasing the channel dosage by using only NO annealing.