Study Of Double-barrier Si Quantum Dot Floating Gate Memory

Tunnel oxide thickness scaling that due to the rapid development of semiconductors is encountering problem for next generation flash memory device. With tunnel oxide shrinking down, the stress-induced leakage current becomes more serious leading to degraded retention. To overcome this problem, silicon quantum dot floating-gate memory was proposed to achieve that discrete charge storage on devices. It is considered as potential candidates of non-volatile memory on future, since low operating voltages, and fast program/erasing speeds and excellent retention characteristics.This thesis describes the development and market prospects of silicon QDs floating gate memory. Introduced the working principle, reliability problems and charge transport mechanism under the quantum effects of silicon QDs floating gate memory. Considered devices should have better performance of P/E speed and the retention after comparison of existing devices structure. The storage characteristics of double barrier Si QDs floating-gate memory analyzed by comparative SiCx, SiNx and SiO2 that is three common parent material used to preparation of QDs, showed that lower barrier of SiCx is more suitable as blocking barrier because floating-gate manufactured by SiCx with a higher conductivity in the same density of QDs. Thus, based SiCx texture double barrier QDs floating-gate memory will have better storage properties.Plasma enhanced chemical vapor deposition(PECVD) is used to deposit a Si quantum-dot(size 5nm) embedded SiC with SiH4 and CH4 as reactant gas. A memory window of 7.7 V was observed for the sample by capacitance-voltage measurements.