A system and method provides an improved source-coupling ratio in flash
memories. In one embodiment, a flash memory cell system with high
source-coupling ratio includes at least a conventional floating gate
device having a floating gate, a drain and a source. The floating gate is
formed over a first junction for charging the floating gate by electron
injection from the source to the floating gate and at least a first
dielectric is layered on top of the floating gate to form a second
junction. At least a first polycrystalline silicon is layered on top of
the first dielectric, the first polycrystalline silicon electrically
connected to the source. Electron tunneling provided through the second
junction to the floating gate charges the floating gate, thereby
increasing the source-coupling ratio of the floating gate and increasing
the efficiency of storing electrical charge.