Hydrogenation and nitridization processes for modifying effective oxide thickness of a film
First Claim
1. A method of forming a structure in a semiconductor device, the method comprising:
- depositing a metal nitride capping layer on a high-k dielectric layer formed over a surface of a substrate;
exposing an exposed surface of the deposited metal nitride capping layer to a plasma that comprises a first gas that comprises a hydrogen containing species and a second gas that comprises a nitrogen containing species, wherein the hydrogen containing species in the first gas comprises nitrogen;
depositing a silicon-containing layer on the exposed surface of the deposited metal nitride capping layer after exposing the exposed surface to the plasma;
performing a thermal anneal process on the silicon-containing layer; and
removing the silicon-containing layer.
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Accused Products
Abstract
Embodiments described herein generally relate to enable the formation of a metal gate structure with a reduced effective oxide thickness over a similar structure formed via conventional methods. A plasma hydrogenation process followed by a plasma nitridization process, or a single-step plasma hydrogenation and nitridization process, is performed on a metal nitride layer in a film stack, thereby, according to some embodiments, removing oxygen atoms disposed within layers of the film stack and, in some embodiments, adding nitrogen atoms to the layers of the film stack. As a result, an effective oxide thickness of the metal gate structure is reduced with little or no accompanying flatband voltage shift.
40 Citations
20 Claims
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1. A method of forming a structure in a semiconductor device, the method comprising:
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depositing a metal nitride capping layer on a high-k dielectric layer formed over a surface of a substrate; exposing an exposed surface of the deposited metal nitride capping layer to a plasma that comprises a first gas that comprises a hydrogen containing species and a second gas that comprises a nitrogen containing species, wherein the hydrogen containing species in the first gas comprises nitrogen; depositing a silicon-containing layer on the exposed surface of the deposited metal nitride capping layer after exposing the exposed surface to the plasma; performing a thermal anneal process on the silicon-containing layer; and removing the silicon-containing layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of forming a structure in a semiconductor device, the method comprising:
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depositing a metal nitride capping layer on a high-k dielectric layer formed over a surface of a substrate; exposing an exposed surface of the deposited metal nitride capping layer to a plasma that comprises a first gas that comprises a hydrogen containing species and a second gas that comprises a nitrogen containing species, wherein the hydrogen containing species in the first gas comprises nitrogen; depositing a sacrificial layer on the high-k dielectric layer; depositing a silicon-containing layer on the sacrificial layer; performing a thermal anneal process on the sacrificial layer and the silicon-containing layer; and removing the sacrificial layer and the silicon-containing layer before depositing a metal nitride capping layer on the high-k dielectric layer.
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10. A method of forming a structure in a semiconductor device, the method comprising:
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depositing a high-k dielectric layer on a semiconductor substrate; depositing on the high-k dielectric layer a capping layer; exposing an exposed surface of the capping layer to a plasma-excited hydrogen species and a plasma-excited nitrogen species; exposing the exposed surface to air; performing a thermal anneal process on the high-k dielectric layer and the capping layer for a particular time and at a particular temperature; depositing a silicon-containing layer on the exposed surface; performing a secondary thermal anneal process on the silicon-containing layer; and removing the silicon-containing layer. - View Dependent Claims (11, 12, 13, 14)
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15. A method of forming a structure in a semiconductor device, the method comprising:
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depositing a high-k dielectric layer on a semiconductor substrate; depositing on the high-k dielectric layer a capping layer; exposing an exposed surface of the capping layer to a plasma-excited hydrogen species and a plasma-excited nitrogen species; exposing the exposed surface to air; performing a thermal anneal process on the high-k dielectric layer and the capping layer for a particular time and at a particular temperature; depositing a sacrificial layer on the high-k dielectric layer; depositing a silicon-containing layer on the sacrificial layer; performing a tertiary thermal anneal process on the sacrificial layer and the silicon-containing layer; and removing the sacrificial layer and the silicon-containing layer.
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16. A method of forming a structure in a semiconductor device, the method comprising:
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depositing a high-k dielectric layer on a semiconductor substrate; depositing on the high-k dielectric layer a capping layer; performing an oxygen-free plasma treatment process on at least one surface of a process chamber; exposing an exposed surface of the capping layer to a plasma-excited hydrogen species and a plasma-excited nitrogen species in the process chamber; exposing the exposed surface to air; and performing a thermal anneal process on the high-k dielectric layer and the capping layer for a particular time and at a particular temperature.
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17. A method of forming a structure in a semiconductor device, the method comprising:
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depositing a high-k dielectric layer on a semiconductor substrate; depositing on the high-k dielectric layer a capping layer; exposing an exposed surface of the capping layer to a plasma-excited hydrogen species and a plasma-excited nitrogen species; exposing the exposed surface to air; performing a thermal anneal process on the high-k dielectric layer and the capping layer for a particular time and at a particular temperature; wherein the plasma-excited hydrogen species comprises ammonia, and the plasma-excited nitrogen species comprises nitrogen gas (N2).
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18. A method of forming a structure in a semiconductor device, the method comprising:
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depositing a high-k dielectric layer on a semiconductor substrate; depositing a capping layer on the high-k dielectric layer to form a portion of the structure, wherein the portion includes the capping layer and the high-k dielectric layer, and wherein the deposited capping layer has an exposed surface; and exposing the exposed surface to a plasma-excited hydrogen species and a plasma-excited nitrogen species, wherein the plasma-excited hydrogen species comprises ammonia, and the plasma-excited nitrogen species comprises nitrogen gas (N2). - View Dependent Claims (19, 20)
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Specification