Semiconductor device and method of forming the same
Methods of forming a semiconductor device include forming an insulation layer on a semiconductor structure, forming an opening in the insulation layer, the opening having a sidewall defined by one side of the insulation layer, forming a first metal layer in the opening, at least partially exposing the sidewall of the opening by performing a wet-etching process on the first metal layer, and selectively forming a second metal layer on the etched first metal layer. An average grain size of the first metal layer is smaller than an average grain size of the second metal layer. Related semiconductor devices are also disclosed.
1. A semiconductor device comprising:
a substrate;
gate interlayer insulation layers and gate patterns alternately stacked on the substrate;
a semiconductor structure extending upwardly from the substrate along sidewalls of the gate interlayer insulation layers and the gate patterns; and
an insulation pattern between the gate patterns and the semiconductor structure,
wherein the gate patterns comprise a first metal pattern and a second metal pattern, the first metal pattern being adjacent to the semiconductor structure, wherein the second metal pattern is in direct contact with the first metal pattern and is spaced apart from the semiconductor structure by the first metal pattern.
2. The semiconductor device of claim 1 , wherein an average grain size of the first metal pattern is smaller than an average grain size of the second metal pattern.
3. The semiconductor device of claim 2 , wherein the second metal pattern defines a second sidewall of the gate patterns facing a first sidewall of the gate patterns adjacent to the semiconductor structure; the second metal pattern protruding more than the insulation pattern on the second sidewall of the gate patterns.
4. The semiconductor device of claim 1 , wherein the insulation pattern extends on the top and bottom surfaces of the gate patterns.
5. The semiconductor device of claim 1 , further comprising a barrier layer between the first metal pattern and the insulation pattern, where one side of the barrier layer opposite the semiconductor structure is coplanar with one side of the first metal pattern.
6. The semiconductor device of claim 1 , wherein the insulation pattern comprises Oxide-Nitride-Oxide-Aluminum Oxide (ONOA).
7. The semiconductor device of claim 1 , wherein the insulation pattern comprises a charge storage layer.
8. The semiconductor device of claim 1 , wherein the insulation pattern provides a gate insulation layer between the first metal pattern and an active pattern in the semiconductor structure in which a channel region of the transistor is provided.
9. A semiconductor device comprising:
a substrate;
gate interlayer insulation layers and gate patterns alternately stacked on the substrate;
a semiconductor structure extending upwardly from the substrate along sidewalls of the gate interlayer insulation layers and the gate patterns, wherein the semiconductor structure penetrates the gate patterns; and
an insulation pattern between the gate patterns and the semiconductor structure;
wherein the gate patterns comprise a first metal pattern and a second metal pattern, the first metal pattern being adjacent to the semiconductor structure, wherein the second metal pattern is spaced apart from the semiconductor structure by the first metal pattern.
10. The semiconductor device of claim 9 , wherein the first metal pattern is electrically connected to the second metal pattern.
11. The semiconductor device of claim 9 , wherein the gate patterns extend along a first direction that crosses a second direction along which the semiconductor structure extends.
12. The semiconductor device of claim 9 , wherein an average grain size of the first metal pattern is smaller than an average grain size of the second metal pattern.
13. The semiconductor device of claim 9 , wherein the second metal pattern defines a second sidewall of the gate patterns facing a first sidewall of the gate patterns adjacent to the semiconductor structure, and wherein the second metal pattern protrudes more than the insulation pattern on the second sidewall of the gate patterns.
14. The semiconductor device of claim 9 , further comprising a barrier layer between the first metal pattern and the insulation pattern, where one side of the barrier layer opposite the semiconductor structure is coplanar with one side of the first metal pattern.