A semiconductor device and a method of forming the semiconductor device are disclosed.
The semiconductor device includes: a semiconductor substrate; a patterned floating
gate formed on the semiconductor substrate, the patterned floating gate having
upper and side parts and corners; and a dielectric layer containing a first oxide
layer, a nitride layer and a second oxide layer deposited over the semiconductor
substrate and the floating gate. The ratio of the thickness of the first oxide
layer in the upper and side parts of the patterned floating gate to the thickness
of the first oxide layer in the corners of the patterned floating gate does not
exceed 1.4. The semiconductor device has an improved coupling coefficient, and
reduced leakage current.
