Characteristic distributions of narrow channel metal-oxide-semiconductor field-effect transistor memories with silicon nanocrystal floating gates

We report the width and length dependences of threshold voltage shift and i ts distribution in narrow channel metal-oxide-semiconductor field-effect tr ansistor (MOSFET) memories based on self-assembling silicon nanocrystals. A s the channel width decreases, the threshold voltage shift, along with its distribution, increases. On the other hand, as the channel length decreases , the threshold voltage shift decreases. These results are well explained b y the random distribution of silicon nanocrystals, in particular the number of dots on the narrow channel. The difference in width and length dependen ces is due to the difference in parallel and serial connections of unit cel ls. Based on the unit cell model, the width and length dependences of the t hreshold voltage shift are calculated and compared with the experimental re sults.