NONVOLATILE SEMICONDUCTOR MEMORY DEVICE AND METHOD OF MANUFACTURING THE SAME

摘要

According to one embodiment, a nonvolatile semiconductor memory device is provided. The element isolation insulating bodies form active areas extending in one direction along a surface of a semiconductor substrate in a surface region of the semiconductor substrate, and partition the surface region into the active areas. The tunnel insulating films are formed on the active areas respectively. The floating gate electrodes are formed on the tunnel insulating films respectively. The inter-gate insulating films are formed on the floating gate electrodes. The control gate electrodes are provided on the inter-gate insulating films. The source regions and drain regions are formed in the active areas respectively. Each of the active areas has steps at side surfaces. A width of a portion of each of the active areas deeper than the steps is larger than that of a portion of each of the active areas shallower than the steps.

主权项

1. A nonvolatile semiconductor memory device comprising:
a semiconductor substrate; element isolation insulating bodies buried in grooves provided in a surface region of the semiconductor substrate to partition the surface region into active areas, the active areas extending in one direction along a surface of the semiconductor substrate and being separated apart from each other; tunnel insulating films formed on the active areas respectively; floating gate electrodes formed on the tunnel insulating films respectively; inter-gate insulating films formed on the floating gate electrodes; control gate electrodes provided on the inter-gate insulating films; and source regions and drain regions which are formed in the active areas respectively, wherein each of the active areas has steps at side surfaces, and a width of a portion of each of the active areas deeper than the steps is larger than that of a portion of each of the active areas shallower than the steps.