Semiconductor switching devices having ferroelectric layers therein and methods of fabricating same
A semiconductor device includes a substrate, a channel on or in the substrate, a source/drain pair respectively on opposite ends of the channel, and a gate structure on the channel between the source/drain pair, wherein the gate structure includes an interfacial layer, a ferroelectric layer, a stabilization layer, an oxygen diffusion barrier layer, and a threshold voltage control layer that are sequentially stacked on the channel.
1 . A method of manufacturing a semiconductor device, comprising:
forming an interfacial layer and a ferroelectric layer sequentially on a substrate;
forming a stabilization layer on the ferroelectric layer;
forming an oxygen diffusion barrier layer on the stabilization layer;
forming a silicon layer on the oxygen diffusion barrier layer; and
annealing the ferroelectric layer, wherein a thickness of the interfacial layer increases by 0 Å to 3 Å during the annealing of the ferroelectric layer.
2 . The method of claim 1 , wherein the stabilization layer comprises at least one material selected from a group consisting of TiN, MON, Mo, Al 2 O 3 , AIN, W, WN, WCN, La, LaO, LaN, TiAIN, and TION.
3 . The method of claim 2 , wherein the stabilization layer comprises MoN.
4 . The method of claim 1 , wherein the oxygen diffusion barrier layer comprises at least one material selected from a group consisting of TiN, AIN, TaN, TiSiN, TION, TiAIN, WCN, WN, and W.
5 . A method of manufacturing a semiconductor device, comprising:
forming an interfacial layer, a ferroelectric layer, a stabilization layer, and a sacrificial layer in sequence on a first region and a second region of a substrate;
annealing the ferroelectric layer;
removing the sacrificial layer;
removing a portion of the stabilization layer on the second region of the substrate;
forming a first threshold voltage control layer on the stabilization layer, on the first region of the substrate; and
forming a second threshold voltage control layer on a portion of the ferroelectric layer, on the second region of the substrate, wherein the stabilization layer is configured to stabilize a ferroelectric phase of the ferroelectric layer such that a ferroelectricity characteristic of the ferroelectric layer is preserved.
6 . The method of claim 5 , wherein a material included in the stabilization layer has a work function that is greater than a work function of a material included in the first threshold voltage control layer.
7 . The method of claim 5 , wherein a material included in the stabilization layer has a work function that is greater than a work function of the material included in the second threshold voltage control layer.
8 . The method of claim 5 , wherein:
forming the first threshold voltage control layer comprises forming a first lower threshold voltage control layer on the stabilization layer on the first region of the substrate and forming a first upper threshold voltage control layer on the first lower threshold voltage control layer, and
forming the second threshold voltage control layer comprises forming a second lower threshold voltage control layer on a portion of the ferroelectric layer on the second region of the substrate and forming a second upper threshold voltage control layer on the second lower threshold voltage control layer.
9 . The method of claim 8 , wherein a material included in the stabilization layer has a work function that is greater than a work function of a material included in the first lower threshold voltage control layer.
10 . The method of claim 8 , wherein a material included in the stabilization layer has a work function that is greater than a work function of the material included in the second lower threshold voltage control layer.
11 . The method of claim 8 , wherein a material included in the stabilization layer has a work function that is greater than a work function of a material included in the first upper threshold voltage control layer.
12 . The method of claim 8 , wherein a material included in the stabilization layer has a work function that is greater than a work function of a material included in the second upper threshold voltage control layer.
13 . The method of claim 8 , wherein a material included in the first lower threshold voltage control layer has a work function that is greater than a work function of a material included in the first upper threshold voltage control layer.
14 . The method of claim 8 , wherein a material included in the second lower threshold voltage control layer has a work function that is greater than a work function of a material included in the second upper threshold voltage control layer.
15 . The method of claim 8 , wherein the first lower threshold voltage control layer and the second lower threshold voltage control layer include a same material; and wherein the first lower threshold voltage control layer and the second lower threshold voltage control layer have different thicknesses from each other.
16 . The method of claim 8 , wherein the first upper threshold voltage control layer and the second lower threshold voltage control layer include a same material.
17 . The method of claim 5 , further comprising forming an oxygen diffusion barrier layer on the stabilization layer before forming the sacrificial layer.
18 . The method of claim 17 , further comprising removing a portion of the oxygen diffusion barrier layer on the second region of the substrate.
19 . A method of manufacturing a semiconductor device, comprising:
forming a channel region in or on a semiconductor substrate;
forming an interfacial layer, a ferroelectric layer, a stabilization layer, an oxygen diffusion barrier layer, and a sacrificial layer sequentially on the channel region;
annealing the ferroelectric layer;
removing the sacrificial layer; and
forming a threshold voltage control layer on the oxygen diffusion barrier layer, wherein the stabilization layer is configured to stabilize a ferroelectric phase of the ferroelectric layer such that a ferroelectricity characteristic of the ferroelectric layer is preserved.