According to one embodiment, a memory cell structure comprises a semiconductor
substrate, a first silicon oxide layer situated over the semiconductor substrate,
a charge storing layer situated over the first silicon oxide layer, a second silicon
oxide layer situated over the charge storing layer, and a gate layer situated over
the second silicon oxide layer. In the exemplary embodiment, the charge storing
layer comprises silicon nitride having reduced hydrogen content, e.g., in the range
of about 0 to 0.5 atomic percent. As a result, the reduced hydrogen content reduces
the charge loss in the charge storing layer. The reduced charge loss in the charge
storing layer has the benefit of reducing threshold voltage shifts, programming
data loss, and programming capability loss in the memory device, thereby improving
memory device performance.