Patent ID: 9620511
Date: 2017-04-11
CPC Classifications: H01L

Claim:
1. A vertical semiconductor device comprising: a first etch stop layer formed on a substrate; a ground selection line, word lines, and a string selection line sequentially formed on the first etch stop layer to be separated from one another in a first direction perpendicular to an upper surface of the substrate; and a channel structure contacting the upper surface of the substrate by penetrating the first etch stop layer, the ground selection line, the word lines, and the string selection line, wherein a portion of the channel structure penetrating the first etch stop layer protrudes in a horizontal direction, wherein the first etch stop layer includes a metal, and wherein a first width of the channel structure in the protruding region in the horizontal direction is larger than a second width of the channel structure in the horizontal direction located on a same level as the ground selection line.