Method and apparatus for fabricating a high dielectric constant transistor gate using a low energy plasma system
First Claim
1. A method of forming a semiconductor device, comprising:
- forming a dielectric layer having a desired thickness on a surface of a substrate;
forming a concentration gradient of a first material within at least a portion of the thickness of the formed dielectric layer using a low energy sputtering process, wherein the low energy sputtering process comprises;
pulsing an RE energy delivered at a first RF frequency and a first RF power to a processing region of a low energy sputtering chamber using an RF generator;
pulsing a DC voltage delivered from a DC source assembly to a target disposed in the processing region; and
synchronizing the pulsed RF energy and the pulsed DC voltage so that an amount of the first material removed from the target can be disposed within the dielectric layer;
exposing the dielectric layer and the first material to an RF plasma comprising nitrogen; and
depositing a second material over the dielectric layer.
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Accused Products
Abstract
The present invention generally provides methods and apparatuses that are adapted to form a high quality dielectric gate layer on a substrate. Embodiments contemplate a method wherein a metal plasma treatment process is used in lieu of a standard nitridization process to form a high dielectric constant layer on a substrate. Embodiments further contemplate an apparatus adapted to “implant” metal ions of relatively low energy in order to reduce ion bombardment damage to the gate dielectric layer, such as a silicon dioxide layer and to avoid incorporation of the metal atoms into the underlying silicon. In general, the process includes the steps of forming a high-k dielectric and then terminating the surface of the deposited high-k material to form a good interface between the gate electrode and the high-k dielectric material. Embodiments of the invention also provide a cluster tool that is adapted to form a high-k dielectric material, terminate the surface of the high-k dielectric material, perform any desirable post treatment steps, and form the polysilicon and/or metal gate layers.
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Citations
37 Claims
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1. A method of forming a semiconductor device, comprising:
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forming a dielectric layer having a desired thickness on a surface of a substrate; forming a concentration gradient of a first material within at least a portion of the thickness of the formed dielectric layer using a low energy sputtering process, wherein the low energy sputtering process comprises; pulsing an RE energy delivered at a first RF frequency and a first RF power to a processing region of a low energy sputtering chamber using an RF generator; pulsing a DC voltage delivered from a DC source assembly to a target disposed in the processing region; and synchronizing the pulsed RF energy and the pulsed DC voltage so that an amount of the first material removed from the target can be disposed within the dielectric layer; exposing the dielectric layer and the first material to an RF plasma comprising nitrogen; and depositing a second material over the dielectric layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of forming a semiconductor device, comprising:
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forming a dielectric layer having a desired thickness on a surface of a substrate; forming a concentration gradient of a first material within at least a portion of the thickness of the formed dielectric layer using a low energy sputtering process, wherein the low energy sputtering process comprises; pulsing an RF energy delivered at a first RF frequency and a first RF power to a processing region of a low energy sputtering chamber using an RF generator; pulsing a DC voltage delivered from a DC source assembly to a target disposed in the processing region; and synchronizing the pulsed RF energy and the pulsed DC voltage so that an amount of the first material removed from the target can be disposed within the dielectric layer; annealing the substrate at a temperature between about 800°
C. and about 1100 °
C.; anddepositing a second material over the dielectric layer. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A method of forming a semiconductor device, comprising:
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positioning a substrate having a dielectric layer disposed on a surface of a substrate in a processing region of a low energy sputtering chamber; forming a concentration gradient of a first material within at least a portion of the thickness of the formed dielectric layer using a low energy sputtering process, wherein the low energy sputtering process comprises; pulsing an RF energy delivered at a first RF frequency and a first power to a first target which comprises the first material, wherein the first frequency is between about 1 MHz and about 200 MHz; pulsing a DC voltage delivered to the target from a DC source assembly; and synchronizing the pulsed RF energy and the pulsed DC voltage. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37)
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Specification