Ts. Yoon et al., High spatial density nanocrystal formation using thin layer of amorphous Si0.7Ge0.3 deposited on SiO2, J APPL PHYS, 87(5), 2000, pp. 2449-2453
The process to make nanocrystals with an average size < 5 nm and a spatial
density > 10(12)/cm(2) was proposed using agglomeration and partial oxidati
on of thin amorphous Si0.7Ge0.3 layer deposited in between the SiO2 layers
by low pressure chemical vapor deposition. The reason to use an amorphous l
ayer is to make it possible to deposit a thin continuous layer with a thick
ness of less than 5 nm. Si0.7Ge0.3 alloy layer was used to control the spat
ial density of the nanocrystals by using selective oxidation of Si in Si0.7
Ge0.3 alloy layer. The single electron memory, similar to a flash type memo
ry device was fabricated using these Si0.7Ge0.3 nanocrystals. The Coulomb b
lockade effect could be clearly observed at room temperature with a thresho
ld voltage shift of about 2.4 V, which demonstrated the formation of nanocr
ystals with a high spatial density. (C) 2000 American Institute of Physics.
[S0021-8979(00)06405-7].