Patent ID: 8981461
Filing Date: 2015-03-17
Classification: G11C,H01L

Abstract:
1. A nonvolatile semiconductor memory device comprising: a semiconductor substrate; a fin-type stacked layer structure in which a first insulating layer, a first semiconductor layer, . . . an n-th insulating layer, an n-th semiconductor layer, and an (n+1)-th insulating layer (n is a natural number equal to or more than 2) are stacked in order thereof in a first direction perpendicular to a surface of the semiconductor substrate and which extends in a second direction parallel to the surface of the semiconductor substrate; first to n-th memory strings which use the first to n-th semiconductor layers as channels respectively; a common semiconductor layer which combines the first to n-th semiconductor layers at first ends of the first to n-th memory strings in the second direction; a drain electrode connected to the common semiconductor layer; a source electrode connected to the first to n-th semiconductor layers at second ends of the first to n-th memory strings in the second direction; and first to n-th layer select transistors arranged in order from the drain electrode to the first to n-th memory strings between the first to n-th memory strings and the drain electrode, wherein the first to n-th layer select transistors comprise first to n-th select gate electrodes extending in the first direction respectively, a drain side edge of an i-th insulating layer (i is one of 2 to n) among the first to (n+1)-th insulating layers is located at the same position as a memory string side edge of an (i−1)-th select gate electrode or located closer to the drain electrode than the memory string side edge of the (i−1)-th select gate electrode, where the drain side edge is a edge which is near the drain electrode, and the memory string side edge is a edge which is near the first to n-th memory strings, and a j-th layer select transistor (j is one of 1 to n) among the first to n-th layer select transistors is normally-on in a j-th semiconductor layer.