A split gate, vertical NROM memory cell is comprised of a plurality of oxide
pillars
that each has a source/drain region formed in the top of the pillar. A trench is
formed between each pair of oxide pillars. A polysilicon control gate is formed
in the trench between the pair of oxide pillars. A polysilicon program gate is
formed between the control gate and each oxide pillar. The program gates extend
along the sidewall of each oxide pillar. A gate insulator layer is formed between
each program gate and the adjacent oxide pillar. Each gate insulator layer has
a structure for trapping at least one charge. In one embodiment, the gate insulator
structure is an oxide-nitride-oxide layer in which the charge is stored at the
trench bottom end of the nitride layer. An interpoly insulator is formed between
the program gates and the control gate.