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 layer on a high-k dielectric layer formed on a semiconductor substrate to form a portion of the structure, wherein the semiconductor substrate is disposed over a substrate supporting surface of a pedestal disposed in a first processing chamber in a cluster tool;
sequentially exposing an exposed surface of the deposited metal nitride layer formed on the semiconductor substrate to a non-oxidizing plasma-excited hydrogen species followed by a plasma-excited nitrogen species while a bias is applied to the semiconductor substrate, which is disposed over a substrate supporting surface of a pedestal disposed in a second processing chamber in the cluster tool;
depositing a silicon-containing layer on the exposed surface;
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 is performed on a metal nitride layer in a film stack, thereby removing oxygen atoms disposed within layers of the film stack and, in some embodiments eliminating an oxygen-containing interfacial layer disposed within 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. Further, the metal gate structure operates with an increased leakage current that is as little as one quarter the increase in leakage current associated with a similar metal gate structure formed via conventional techniques.
39 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 layer on a high-k dielectric layer formed on a semiconductor substrate to form a portion of the structure, wherein the semiconductor substrate is disposed over a substrate supporting surface of a pedestal disposed in a first processing chamber in a cluster tool; sequentially exposing an exposed surface of the deposited metal nitride layer formed on the semiconductor substrate to a non-oxidizing plasma-excited hydrogen species followed by a plasma-excited nitrogen species while a bias is applied to the semiconductor substrate, which is disposed over a substrate supporting surface of a pedestal disposed in a second processing chamber in the cluster tool; depositing a silicon-containing layer on the exposed surface; performing a thermal anneal process on the silicon-containing layer; and removing the silicon-containing layer. - View Dependent Claims (2, 3, 4, 5)
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6. A method of forming a structure in a semiconductor device, the method comprising:
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depositing a sacrificial metal nitride layer on a high-k dielectric layer formed on a semiconductor substrate; depositing a silicon-containing layer on the sacrificial metal nitride layer; performing a thermal anneal process on the sacrificial metal nitride layer and the silicon-containing layer; removing the sacrificial metal nitride layer and the silicon-containing layer; depositing a metal nitride layer on the high-k dielectric layer to form a portion of the structure, wherein the semiconductor substrate is disposed over a substrate supporting surface of a pedestal disposed in a first processing chamber in a cluster tool; and sequentially exposing an exposed surface of the deposited metal nitride layer formed on the semiconductor substrate to a non-oxidizing plasma-excited hydrogen species followed by a plasma-excited nitrogen species while a bias is applied to the semiconductor substrate, which is disposed over a substrate supporting surface of a pedestal disposed in a second processing chamber in the cluster tool. - View Dependent Claims (7, 8)
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9. A method of forming a structure in a semiconductor device, the method comprising:
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exposing a surface of a second process chamber to an oxygen-free plasma; depositing a metal nitride layer on a high-k dielectric layer formed on a semiconductor substrate to form a portion of the structure, wherein the semiconductor substrate is disposed over a substrate supporting surface of a pedestal disposed in a first processing chamber in a cluster tool; and sequentially exposing an exposed surface of the deposited metal nitride layer formed on the semiconductor substrate to a non-oxidizing plasma-excited hydrogen species followed by a plasma-excited nitrogen species while a bias is applied to the semiconductor substrate, which is disposed over a substrate supporting surface of a pedestal disposed in the second processing chamber in the cluster tool. - View Dependent Claims (10, 11, 12)
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13. 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, wherein the semiconductor substrate is disposed over a pedestal; depositing a metal nitride layer on the high-k dielectric layer; sequentially exposing an exposed surface of the metal nitride layer to a non-oxidizing plasma-excited hydrogen species followed by a plasma-excited nitrogen species, while a bias is applied to the pedestal; exposing the exposed surface to air after sequentially exposing the exposed surface to the non-oxidizing plasma-excited hydrogen species followed by the plasma-excited nitrogen species; and annealing the high-k dielectric layer and the metal nitride layer after exposing the exposed surface to air. - View Dependent Claims (14, 15, 16)
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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, wherein the semiconductor substrate is disposed over a pedestal; depositing a metal nitride layer on the high-k dielectric layer to form a portion of the structure while a bias is applied to the pedestal; and reducing a first effective oxide thickness of the metal nitride layer to a second effective oxide thickness by sequentially exposing an exposed surface of the metal nitride layer to a non-oxidizing plasma-excited hydrogen species followed by a plasma-excited nitrogen species, wherein the non-oxidizing plasma-excited hydrogen species are generated from a first process gas, the first process gas comprising hydrogen gas (H2), and wherein the plasma-excited nitrogen species are generated from a second process gas, the second process gas comprising nitrogen gas (N2) and ammonia (NH3). - View Dependent Claims (18)
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19. A method of forming a structure in a semiconductor device, the method comprising:
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performing an oxygen-free plasma treatment process on a process chamber in which an exposed surface of the process chamber is exposed to a non-oxidizing plasma-excited hydrogen species; depositing a high-k dielectric layer on a semiconductor substrate, wherein the semiconductor substrate is disposed over a pedestal; depositing a metal nitride layer on the high-k dielectric layer to form a portion of the structure while a bias is applied to the pedestal, the pedestal disposed in the process chamber; and reducing a first effective oxide thickness of the metal nitride layer to a second effective oxide thickness by sequentially exposing an exposed surface of the metal nitride layer to the non-oxidizing plasma-excited hydrogen species followed by a plasma-excited nitrogen species. - View Dependent Claims (20)
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Specification