As we enter the nanotechnology era, a big shift in paradigm comes to the memory industry. The traditional computer industry for dynamic RAM is expected to mature its memory-bit consumption with a relatively low growth rate. Meanwhile, the memory consumption and high-density memory usage in mobile handsets and digital consumer applications will grow very fast. For these new applications, NAND Flash memory will be the key enabling technology and its easy scaling and multibit/cell capabilities require a new memory growth model. The well-known Moore's law still holds for most cases after the quarter-century history of the integrated circuit industry. However, the paradigm shift in the memory industry requires a new memory growth model: "a twofold increase per year in memory density." This paper will cover some details of recent memory technologies, application trends, and the proposed new memory growth model.

A two-dimensional device simulator SNU-2D based on the hydrodynamic model is developed for the simulation and analysis of submicron devices. The simulator has the capacity for both self-consistent steady-state and transient-state simulation. To obtain better convergence and numerical stability, we adopt an improved discretization scheme for the carrier energy flux equation and a new strategy for the transient simulation. In steady-state simulation the new discretization scheme shows a considerable improvement in convergence rate and numerical accuracy compared with the existing schemes. A transient simulation study is carried out on a deep submicron n-MOSFET used in the sense amplifier of SRAM cells to investigate the gate-switching characteristic. It is found that the behavior of carrier temperature is quasi-static during the switching time even for very fast switching speed, while the behavior of impact ionization under transient mode deviates from that under dc mode as the switching speed increases.>