US Patent 7732853 Multi-bit nonvolatile memory devices including nano-crystals and trench

Nonvolatile integrated circuit memory devices having a 2-bit memory cell include a substrate, a source region and a drain region in the substrate, a step recess channel between the source region and the drain region, a trapping structure including a plurality of charge trapping nano-crystals on the step recess channel, and a gate on the trapping structure. Related fabrication methods are also described.