A method for manufacturing a memory device having a metal nanocrystal
charge storage structure. A substrate is provided and a first layer of
dielectric material is grown on the substrate. A layer of metal oxide
having a first heat of formation is formed on the first layer of
dielectric material. A metal layer having a second heat of formation is
formed on the metal oxide layer. The second heat of formation is greater
than the first heat of formation. The metal oxide layer and the metal
layer are annealed which causes the metal layer to reduce the metal oxide
layer to metallic form, which then agglomerates to form metal islands.
The metal layer becomes oxidized thereby embedding the metal islands
within an oxide layer to form a nanocrystal layer. A control oxide is
formed over the nanocrystal layer and a gate electrode is formed on the
control oxide.