US Patent 7714374 Structure and fabrication method of flash memory

A method for forming a flash memory cell and the structure thereof is disclosed. The flash memory cell includes a substrate, a first raised source/drain region and a second raised source/drain region separated by a trench in-between, a first charge-trapping spacer and a second charge-trapping spacer respectively on the sidewall of the first and second raised source/drain region, a gate structure covering the first and second spacers, the trench and the first and second raised source/drain regions and a gate oxide layer located between the gate structure and the first and second raised source/drain regions and the substrate. By forming the charge-trapping spacers with less e-distribution, the flash memory affords better erasure efficiency.