Methods of Fabricating Semiconductor Devices

A method of fabricating a semiconductor device, the method comprising:

• forming a stacked structure in which 2n first material layers and 2n second material layers are stacked on a substrate, each of the first material layers and each of the second material layers being alternately deposited on each other;
• and
• forming 2n−1 recesses penetrating a quantity of from 20 to 2n−1 of the first material layers, respectively, so as that the 2n−1 recesses expose the quantity of 2n−1 of the first material layers from the substrate at bottoms of the recesses, respectively,
• wherein the 2n−1 recesses are formed by a combination of etch processes for penetrating 2k first material layers, and
• wherein n is an integer that is greater than or equal to two and k is an integer in a range from 0 to n−1.

A method of fabricating a semiconductor device, the method comprising:

• forming a stacked structure in which 2n (here, n is an integer which is 2 or more) deposited sacrificial layers and 2n deposited insulating layers disposed on the 2n deposited sacrificial layers respectively are alternately deposited in a third direction that is perpendicular to a first direction and a second direction on a substrate having an upper surface extending in the first and second directions which are perpendicular to each other;
• forming a recess group including 2n−1 first recesses penetrating 2n through 2n−1 deposited sacrificial layers, respectively, from an uppermost deposited sacrificial layer of the 2n deposited sacrificial layers;
• forming a buried insulating layer group including 2n−1 buried insulating layers filling the 2n−1 first recesses respectively;
• and
• forming a contact plug group including 2n contact plugs penetrating an uppermost deposited insulating layer of the 2n deposited insulating layers and the 2n−1 buried insulating layers, respectively,
• wherein n is an integer that is at least 2, and
• wherein forming the recess group is performed by n etch processes to remove a portion of the stacked structure.