Semiconductor memory device and method of manufacturing the same.

摘要

In a semiconductor memory device having a floating gate structure, the floating gate electrode (30) is composed of 2 to 10 silicon grains. With the floating gate electrode, the insulation film (31), formed on the floating gate electrode, can have a high breakdown voltage. In a method of manufacturing a semiconductor memory device having a floating gate structure, an insulation film (23) is formed on the silicon substrate (21), portions of the insulation film which are on the drain and source forming regions of the silicon substrate are removed, and a silicon layer (24a) is formed on the silicon substrate (21) by an epitaxial growth process, constituting a floating gate, composed of 2 to 10 silicon grains. According to the manufacturing method, the insulation film (31) formed on the floating gate electrode can have a high breakdown voltage.