A storage device structure (10) has two bits of storage per control gate
(34) and uses source side injection (SSI) to provide lower programming
current. A control gate (34) overlies a drain electrode formed by a doped
region (22) that is positioned in a semiconductor substrate (12). Two
select gates (49 and 50) are implemented with conductive sidewall spacers
adjacent to and lateral to the control gate (34). A source doped region
(60) is positioned in the semiconductor substrate (12) adjacent to one of
the select gates for providing a source of electrons to be injected into
a storage layer (42) underlying the control gate. Lower programming
results from the SSI method of programming and a compact memory cell size
exists.