Dynamic Random Access Memory (DRAM) Cells with integrated high-k dielectrics
There are a number of solid-state memory technologies [see NVM-project at IHP] that are currently being mass-produced or are being aggressively pursued in the research laboratories [1]. The vision in the field is mass production of the so-called “universal memory cell”, integrated in the conventional Si process technology. The “universal memory cell” is a concept which unifies the advantages of the various solid-state memory approaches nowadays manufactured, namely non-volatile data retention, high scalability, quick read and write times, long endurance and low power characteristics. Flash [2] as well as resistive, magnetoresistive and ferroelectric random access memory cells (RRAM, FeRAM [3] and MRAM [4]) are among the most promising approaches nowadays discussed in the literature. However, in particular the storage density of these technologies is far behind the integration levels of the well-established memory technologies in semiconductor devices, such as non-volatile magnetic hard disc drives and volatile semiconductor memories (static and dynamic random access memory cells (SRAM and DRAM)). Therefore, until any competitive universal memory cell technology will appear on the market, the thirst for storage space will force technology drivers to fully exploit the potential of these classical memory approaches.