Semiconductor device and method for fabricating the same
A semiconductor device that includes: first conductive lines; second conductive lines disposed over the first lines to be spaced apart from the first lines; and a selector layer disposed between the first lines and the second lines and including a dielectric material and a dopant doped with a uniform dopant profile.
1 . A method for fabricating a semiconductor device comprising:
forming trenches on a dielectric material formed over a substrate;
forming first conductive lines in the trenches such that first conductive lines and first dielectric layers are arranged over the substrate;
forming partition layers over the first dielectric layers at a first center-to-center distance between adjacent first dielectric layers, wherein the first center-to-center distance is twice a center-to-center distance between adjacent first conductive lines, and wherein the partition layers include a dielectric material;
forming a dielectric material layer to be formed as a selector layer over the first conductive lines, the first dielectric layers and the partition layers; and
forming an initial selector layer by performing a first ion implantation of a dopant into the dielectric material layer at a first tilt angle and by performing a second ion implantation of the dopant into the dielectric material layer at a second tilt angle,
wherein the first tilt angle is in an opposite direction to the second tilt angle with respect to a line perpendicular to surfaces of the layers, and
the initial selector layer has a uniform dopant profile.
2 . The method according to claim 1 , further comprising:
forming second dielectric layers to cover a structure in which the initial selector layer; and
forming the selector layer by performing a planarization process to expose the partition layers.
3 . The method according to claim 2 , where the selector layer includes a first portion and a second portion,
the first portion is disposed over the first conductive lines, and the second portion is disposed over the first dielectric layers and below the second dielectric layers,
a first side wall of the first portion is in contact with an adjacent partition layer, and an upper portion of a second sidewall of the first portion is in contact with an adjacent second dielectric layer and a lower portion of the second sidewall of the first portion is in contact with the second portion, and
first and second sidewalls of the second portion are in contact with the first portion.
4 . The method according to claim 2 , wherein the selector layer has a uniform dopant profile.
5 . The method according to claim 1 , wherein the first tilt angle is an angle of 45 to 85 degrees with respect to the line perpendicular to the surfaces of the layers and the second tilt angle is an angle of 45 to 85 degrees with respect to the line perpendicular to the surfaces of the layers.
6 . The method according to claim 1 , wherein the dielectric material layer includes silicon oxide, titanium oxide, aluminum oxide, tungsten oxide, hafnium oxide, tantalum oxide, niobium oxide, silicon nitride, titanium nitride, aluminum nitride, tungsten nitride, hafnium nitride, tantalum nitride, niobium nitride, silicon oxynitride, titanium oxynitride, aluminum oxynitride, tungsten oxynitride, hafnium oxynitride, tantalum oxynitride, or niobium oxynitride, or a combination of two or more of silicon oxide, titanium oxide, aluminum oxide, tungsten oxide, hafnium oxide, tantalum oxide, niobium oxide, silicon nitride, titanium nitride, aluminum nitride, tungsten nitride, hafnium nitride, tantalum nitride, niobium nitride, silicon oxynitride, titanium oxynitride, aluminum oxynitride, tungsten oxynitride, hafnium oxynitride, tantalum oxynitride, or niobium oxynitride.
7 . The method according to claim 1 , wherein the dopant includes one or more selected from boron (B), nitrogen (N), carbon (C), phosphorous (P), arsenic (As), aluminum (Al), silicon (Si) and germanium (Ge).
8 . The method according to claim 1 , wherein the partition layer, the first dielectric layer and the second dielectric layer include a same dielectric material as each other, or different dielectric materials from each other.
9 . The method according to claim 2 , further comprising forming a variable resistance layer over or below the selector layer.