Submicron nonvolatile memory cell based on reversible phase transition in chalcogenide glasses

Electrically rewritable nonvolatile memories using chalcogenide semiconduct ors were studied. The memory cell size was changed from 0.3 to 1.5 mum phi using a focused ion beam. This material can be used for nonvolatile random access memory. Reversible phase transition between the amorphous and crysta lline states, which is accompanied by a considerable change in electrical r esistivity, is exploited to store bits of information. The currents for wri te/erase were decreased with reducing memory cell size. In the memory cell of 0.6 mum phi, more than 10(4) repetition cycles of the phase transition w ere attained by the electric pulses. The voltages for the crystallization a nd amorphization processes were 2V and 2.2 V, respectively.