Semiconductor devices with bonding layers
View Patent ↗A method includes the following steps. A transistor including a first gate structure is formed on a first substrate. A first dielectric layer is deposited over the transistor using plasma enhanced atomic layer deposition (PEALD). A multilayer stack is formed on a second substrate. The multilayer stack comprises alternately stacked semiconductor layers and sacrificial layers. A second dielectric layer is deposited over the multilayer stack using a plasma enhanced atomic layer deposition (PEALD). The second dielectric layer is bonded with the first dielectric layer. The sacrificial layers are replaced with a second gate structure.
1 . A method, comprising:
forming a transistor including a first gate structure on a first substrate;
depositing a first dielectric layer over the transistor using plasma enhanced atomic layer deposition (PEALD);
forming a multilayer stack on a second substrate, the multilayer stack comprising alternately stacked semiconductor layers and sacrificial layers;
depositing a second dielectric layer over the multilayer stack using a plasma enhanced atomic layer deposition (PEALD);
bonding the second dielectric layer with the first dielectric layer; and
replacing the sacrificial layers with a second gate structure.
2 . The method of claim 1 , wherein depositing the first dielectric layer is performed at a temperature in a range from 260° C. to 400° C.
3 . The method of claim 1 , further comprising:
after depositing the first dielectric layer, performing a plasma treatment to the first dielectric layer.
4 . The method of claim 3 , wherein the plasma treatment is performed using O 2 , H 2 , NH 3 , or a combination thereof.
5 . The method of claim 3 , wherein after performing the plasma treatment to the first dielectric layer, the first dielectric layer has a top portion having an oxygen atomic concentration greater than an oxygen atomic concentration of a bottom portion of the first dielectric layer.
6 . The method of claim 3 , wherein after performing the plasma treatment to the first dielectric layer, the first dielectric layer has a top portion having a nitrogen atomic concentration greater than a nitrogen atomic concentration of a bottom portion of the first dielectric layer.
7 . The method of claim 1 , wherein the bonded first and second dielectric layers have a gradient oxygen concentration increasing from a bottom surface of the first dielectric layer to an interface between the first and second dielectric layers.
8 . The method of claim 7 , wherein the gradient oxygen concentration in the bonded first and second dielectric layers decreases from the interface between the first and second dielectric layers to a top surface of the second dielectric layer.
9 . A method, comprising:
forming a first transistor over a substrate;
forming a first bonding dielectric layer over the first transistor;
treating the first bonding dielectric layer to form silanol bonds within the first bonding dielectric layer;
after treating the first bonding dielectric layer, bonding a multilayer stack to the first bonding dielectric layer using a second bonding dielectric layer; and
forming a second transistor using one or more semiconductor layers in the multilayer stack.
10 . The method of claim 9 , further comprising:
treating the second bonding dielectric layer to form silanol bonds within the second bonding dielectric layer.
11 . The method of claim 10 , wherein the second bonding dielectric layer is treated using O 2 plasma, H 2 plasma, NH 3 plasma, or a combination thereof.
12 . The method of claim 9 , wherein the first bonding dielectric layer is treated using O 2 plasma, H 2 plasma, NH 3 plasma, or a combination thereof.
13 . The method of claim 9 , wherein forming the first bonding dielectric layer is performed at a temperature in a range from 260° C. to 400° C.
14 . A method, comprising:
forming first semiconductor channels extending in a first direction above a first substrate;
forming a first gate wrapping around the first semiconductor channels;
forming a first dielectric layer over the first gate, wherein the first dielectric layer has a top portion and a bottom portion having different compositions;
forming a second dielectric layer in contact with the first dielectric layer;
forming second semiconductor channels extending in the first direction above the first substrate; and
forming a second gate wrapping around the second semiconductor channels.
15 . The method of claim 14 , wherein the top portion of the first dielectric layer has an oxygen atomic concentration different from an oxygen atomic concentration of the bottom portion of the first dielectric layer.
16 . The method of claim 14 , wherein the top portion of the first dielectric layer has an oxygen atomic concentration greater than an oxygen atomic concentration of the bottom portion of the first dielectric layer.
17 . The method of claim 14 , wherein the top portion of the first dielectric layer has a nitrogen atomic concentration different from a nitrogen concentration of the bottom portion of the first dielectric layer.
18 . The method of claim 14 , wherein the top portion of the first dielectric layer has a nitrogen atomic concentration greater than a nitrogen concentration of the bottom portion of the first dielectric layer.
19 . The method of claim 14 , wherein the second dielectric layer has a top portion and a bottom portion having different compositions.
20 . The method of claim 14 , wherein the first dielectric layer and the second dielectric layer are silicon oxide.