Three dimensional semiconductor memory device and method of fabricating the same
Provided are a three dimensional semiconductor memory device and a method of fabricating the same. The method includes forming a stepwise structure by using mask patterns and a sacrificial mask pattern formed on the mask patterns as a consumable etch mask.
1. A three dimensional semiconductor device comprising:
a substrate comprising a cell array region and a contact region;
an interconnection structure comprising a plurality of stacked horizontal electrodes overlying the substrate; and
bit lines disposed on the cell array region,
wherein widths of the horizontal electrodes decrease as the horizontal electrodes are further away from the substrate, so that the interconnection structure has a stepwise shape in the contact region,
a sidewall of one of the horizontal electrodes meets the below equation
L
n
(
y
m
)
-
L
n
(
y
0
)
<
L
n
(
y
0
)
-
L
n
+
1
(
y
0
)
s
,
within a range of y m meeting the condition of |y m −y 0 |<y 1 ,
where y 0 is a y coordinate of a reference point, y m is a y coordinate of a measured point, L n (y m ) is a distance between a sidewall of a n-th conductive pattern in which the y coordinate is y m , and a sidewall of the bit line most adjacent to the sidewall of the n-th conductive pattern, s is a value between about 2 to 20, and y 1 is a length shorter than a length of bit line.
2. The three dimensional semiconductor device of claim 1 , wherein the parameter y is about 80% to about 100% of the length of the bit line.
3. The three dimensional semiconductor device of claim 1 , wherein the parameter y 1 is about 80% to about 120% of a distance between adjacent two bit lines.
4. The three dimensional semiconductor device of claim 1 , wherein one of the horizontal electrodes comprises two portions having different thicknesses respectively in the contact region, thus having a stepwise shape.
5. The three dimensional semiconductor device of claim 1 , wherein the semiconductor device is included in an SSD.