Effects of Annealing Temperature in a Metal Alloy Nano-dot Memory

The annealing temperature dependence of the capacitance-voltage (C-V) characteristic has been studied in a metal-oxide semiconductor structure containing Fe Pt nano-dots. Several in-situ annealing temperatures from 400 to similar to 700 degrees C in a high vacuum ambience (under 1 x 10(-5) Pa) were evaluated in view of the cell's characteristics and its reliability. Here, we demonstrate that the annealing temperature is significant for memory performance in an alloy metal nano-dot structure. A higher in-situ temperature provides better retention and a more reliable memory window. In the sample with an in-situ annealing condition of 700 degrees C for 30 min, a memory window of 9.2 V at the initial stage was obtained, and a memory window of 6.2 V after 10 years was estimated, which is reliable for a non-volatile memory. From these results, the annealing condition for an alloy metal nano-dot memory is one of the critical parameters for the memory characteristics, and should be optimized for better memory performance.