A Trap Read Only Memory (TROM) architecture employs a NAND-type array
structure configured as a read-only memory that is programmed only one
time. The memory cells in the array comprise a gate terminal, a first
channel terminal (source/drain), a second channel terminal (drain/source)
and a channel region between the first and second channel terminals. A
charge trapping structure, such as a layer of silicon nitride, is formed
over the channel region. A tunneling dielectric is placed between the
channel region and the charge trapping structure, and a blocking
dielectric is placed between the charge trapping structure and the gate
terminal. An E-field assisted (Fowler-Nordheim FN) tunneling program
algorithm is applied.