Dependence of nanocrystal formation and charge storage/retention performance of a tri-layer memory structure on germanium concentration and tunnel oxide thickness
Name
AMMNS003.pdf
Size
911.21 KB
Format
Adobe PDF
Checksum (MD5)
f6e4b3be9d71b5ae89177eff7d0288a3
Author(s)
Teo, L.W.
Ho, Van Tai
Tay, M.S.
Choi, Wee Kiong
Chim, Wai Kin
Antoniadis, Dimitri A.
Fitzgerald, Eugene A.
Date Issued
January 2004
Series/Report no.
Advanced Materials for Micro- and Nano-Systems (AMMNS);
Abstract
The effect of germanium (Ge) concentration and the rapid thermal oxide (RTO) layer thickness on the nanocrystal formation and charge storage/retention capability of a trilayer metal-insulator-semiconductor device was studied. We found that the RTO and the capping oxide layers were not totally effective in confining the Ge nanocrystals in the middle layer when a pure Ge middle layer was used for the formation of nanocrystals. From the transmission electron microscopy and secondary ion mass spectroscopy results, a significant diffusion of Ge atoms through the RTO and into the silicon (Si) substrate was observed when the RTO layer thickness was reduced to 2.5 nm. This resulted in no (or very few) nanocrystals formed in the system. For devices with a Ge+SiO₂ co-sputtered middle layer (i.e., lower Ge concentration), a higher charge storage capability was obtained than with devices with a thinner RTO layer, and the charge retention time was found to be less than in devices with a thicker RTO layer.
Subjects
Ge nanocrystal
floating gate
metal-insulator-semiconductor
Persistent DSpace Link
