Simulation of thermally actuated nano-electro-mechanical memory

An integrated thermal-mechanical simulation of buckling in nano-mechanical memory is performed. The preliminary system is a bridge with a length of 20 microns, a width of 1 micron, and a thickness of 300 nm, in air with a pressure of 5 kPa. Conduction along the bridge as well as convection between the beam and the gas are considered. Simulations are performed for silicon with different dimensions. Longer structures will buckle faster at less temperature and will require less energy to actuate. However, the ideal array would use the smallest beams possible because the data storage density is inversely proportional to the area. The current work suggests the length of 20 microns for the unit of the bridge to balance these constraints. As the thickness of the bridge increases, the energy consumption increases due to an increase of moment of inertia. The buckling time increases by increasing the thickness and the width. Simulations were repeated for silicon carbide, PMMA, and Parylene. Among the beams with the fixed dimension, plastic materials show the fastest write time, with the lowest energy cost. The study of high particle energy collision shows these particles do not cause fast undesired buckling for silicon and silicon carbide. The heat through collision dissipates in less than 10 nsec which is much smaller than the smallest buckling time. However, high energy electron collision causes buckling in PMMA and parylene limiting their use in high radiation applications.