The memory device has a plurality of dielectric films including charge storage
layers CS having a charge holding capability therein and stacked on an active region
of a semiconductor SUB and electrodes G on the plurality of dielectric films. Each
charge storage layer CS includes a first nitride film CS1 made of silicon
nitride or silicon oxynitride and a second nitride film CS2 made of silicon
nitride or silicon oxynitride and having a higher charge trap density than the
first nitride film CS1. The first nitride film CS1 is formed by chemical
vapor deposition using a first gas which contains a first silicon-containing gas
containing chlorine with a predetermined percent composition and a nitrogen-containing
gas as starting materials. The second nitride film CS2 is formed by chemical
vapor deposition using a second gas which contains a second silicon-containing
gas having a lower chlorine percent composition than the above predetermined percent
composition and a nitrogen-containing gas as starting materials.
