Study of structure of Si QDs memory with double barrier and its programming mechanism

Abstract

SiC x thin films with silicon quantum dots(QDs) were prepared by plasma enhanced chemical vapor deposition (PECVD) and thermal annealing. Transmission electron microscopy (TEM) observation shows that a large number of silicon QDs growing in SiC x films. Memory structure with double barrier which consist of SiC x thin films embedded in silicon QDs were prepared. TEM observations shows that the above process successfully prepared Si 3 N 4 /SiC x /Si-QDs/SiC x /SiO 2 double-barrier memory structure. The programming mechanism of double-barrier silicon quantum dot memory was analyzed theoretically in consideration of coulomb blockade effects and quantum confinement effect of silicon quantum QDs. The threshold voltage shift model of double-barrier structure was established. Simulation of that mode shows that threshold voltage shift of double barrier memory is larger than a single barrier memory and double-barrier memory programming faster too. C - V characteristic tests of storage structure shows that double-barrier structure has good storage carrier storage effect, getting about 10 V's the storage window when the scan voltage is ±12 V.