Split gate cell with phonon assisted ballistic CHE injection

A planar channel split floating gate memory cell with an ultra short channel of <40 nm (within 3-4/spl times/ of the electron mean free path) is presented, in which high energy channel hot electrons generated by ballistic channel transport can be injected by phonon scattering with slight energy loss. This planar channel device can match the <1 /spl mu/s program speed of the previously reported step channel ballistic device at the same low voltages of Vd=5 V, Vcg=5 V. The structural differences between a planar and step channel are evaluated.