US9799494B2
Active / In Force
US
⏱️ 9.4 years remaining
Energetic negative ion impact ionization plasma
Assignee: Tokyo Electron Ltd
•
Filing: 2016-04-01
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Granted: 2017-10-24
•
Expires: 2036-04-01
Abstract
Abstract A processing method and system are provided for processing a substrate with a plasma in the presence of an electro-negative gas. A processing gas is injected into a processing chamber. The gas includes a high electron affinity gas species. A surface is provided in the plasma chamber onto which the gas species has a tendency to chemisorb. The gas species is exposed to the surface, chemisorbed onto it, and the surface is exposed to energy that causes negative ions of the chemisorbed gas species, that interact in the plasma to release secondary electrons. A neutralizer grid may be provided to separate from the chamber a second chamber in which forms a low energy secondary plasma for processing the substrate that is dense in electrons and contains high energy neutrals of the gas species and high energy positive ions of processing gas. Pulsed energy may be used to excite plasma or bias the substrate. A hollow cathode source is also provided.
Inventors
- 👤 Lee Chen
- 👤 Merritt Funk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:51
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32431; H01J37/32532; H01J37/32596; H01J37/32009; H01J37/32357; H01J37/32422; H01J37/32458; H01J37/32467; C; C23; C23C; C23C16/00; C23C16/44; C23C16/50; C23C16/515; C23C16/517; H01L21/3065; H10; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/242
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
103 words
A method of processing a substrate with a plasma in the presence of an electro-negative gas, comprising: injecting a processing gas that includes a gas species selected from the group consisting of Cl 2 , F 2 , Br 2 , SiCl 4 , and SiF 4 into a plasma chamber; exposing the gas species in the plasma chamber to a surface to chemisorb the gas species onto the surface; igniting a plasma in the plasma chamber; exposing the surface to energy to cause the emission of negative ions from chemisorbed gas species into the plasma; and processing the substrate using the plasma.
Claim 2
Independent Claim
103 words
A method of processing a substrate with a plasma in the presence of an electro-negative gas, comprising: injecting a processing gas that includes a gas species selected from the group consisting of Cl 2 , F 2 , Br 2 , SiCl 4 , and SiF 4 into a plasma chamber; exposing the gas species in the plasma chamber to a surface to chemisorb the gas species onto the surface; igniting a plasma in the plasma chamber; exposing the surface to energy to cause the emission of negative ions from chemisorbed gas species into the plasma; and processing the substrate using the plasma.
Claim 3
Dependent Claim
30 words
The method of claim 1 further comprising: igniting the plasma by applying a pulsed RF signal to an electrode operably coupled to the plasma chamber to form a pulsed plasma.
Claim 4
Dependent Claim
36 words
The method of claim 1 further comprising: applying a pulsed voltage to the substrate that alternates the bias of the substrate between a negative bias voltage level and a less negative or positive bias voltage level.
Claim 5
Dependent Claim
21 words
The method of claim 1 wherein: the exposing of the surface includes applying a time average negative potential on the surface.
Claim 6
Dependent Claim
51 words
The method of claim 2 , wherein: the exposing of the surface includes impacting the surface with radiation from the pulsed plasma to release negative ions of the gas species into the pulsed plasma and interacting the negative ions with a non-ionized portion of the processing gas to emit energized electrons.
Claim 7
Dependent Claim
18 words
The method of claim 5 , wherein the interacting includes neutralizing the negative ions to emit energized electrons.
Claim 8
Dependent Claim
16 words
The method of claim 6 further comprising: energizing a second plasma with the emitted energized electrons.
Claim 9
Dependent Claim
100 words
The method of claim 7 , further comprising: exposing the substrate to the second plasma; applying a pulsed DC bias to the substrate positioned on a substrate support in the plasma chamber; and periodically biasing the substrate positioned on the substrate support between first and second bias levels, the first bias level being more negative than the second bias level, wherein the substrate and the substrate support, when biased at the first bias level, attract mono-energetic positive ions from the plasma toward the substrate and are operable to enhance a selected chemical etch process at a surface of the substrate.
Claim 10
Dependent Claim
36 words
The method of claim 2 , further comprising: increasing an electron density of the pulsed plasma by emitting negative ions from a secondary electron source that are reactive to a non-ionized portion of the processing gas.
Claim 11
Dependent Claim
15 words
The method of claim 9 , further comprising: neutralizing negative ions to emit energized electrons.
Claim 12
Dependent Claim
30 words
The method of claim 10 , further comprising: energizing a secondary plasma in a portion of the plasma chamber between the plasma and the substrate with the emitted energized electrons.
Claim 13
Dependent Claim
72 words
The method of claim 11 , further comprising: positioning the substrate on a substrate support and applying a pulsed DC bias to the substrate on the substrate support; and periodically biasing the substrate between first and second bias levels, the first bias level being more negative than the second bias level, wherein the substrate, when biased at the first bias level, attracts mono-energetic positive ions from the pulsed plasma toward the substrate.
Claim 14
Dependent Claim
99 words
The method of claim 1 , wherein: the exposing of the gas species and the igniting of the plasma are carried out in a first plasma sub-chamber within the plasma chamber having a said surface therein, the ignited plasma being a primary plasma, the negative ions increasing an electron density in the primary plasma by being neutralized in the primary plasma to thereby emit energized secondary electrons; and the processing of the substrate is carried out in a second plasma sub-chamber having the substrate therein by forming a secondary plasma in the second sub-chamber with the energized secondary electrons.
Claim 15
Dependent Claim
80 words
The method of claim 13 , wherein the substrate is positioned on a substrate holder in the second plasma sub-chamber, the method further comprising: applying a pulsed DC bias to the substrate positioned on the substrate holder; and periodically biasing the substrate between first and second bias levels, the first bias level being more negative than the second bias level, wherein the substrate, when biased at the first bias level, attracts mono-energetic positive ions from the plasma toward the substrate.
Claim 16
Independent Claim
110 words
A method of processing a substrate with a plasma in the presence of an electro-negative gas, comprising: injecting a processing gas that includes a first gas species and a second gas species of higher electron affinity than the first gas species into a plasma chamber; chemisorbing the second gas species onto a surface in the plasma chamber, wherein the surface is different than a surface of the substrate; igniting a plasma in the plasma chamber; exposing the surface to energy to cause the emission of negative ions from chemisorbed second gas species into the plasma; and processing the substrate in the plasma chamber using the plasma containing the negative ions.
Claim 17
Independent Claim
110 words
A method of processing a substrate with a plasma in the presence of an electro-negative gas, comprising: injecting a processing gas that includes a first gas species and a second gas species of higher electron affinity than the first gas species into a plasma chamber; chemisorbing the second gas species onto a surface in the plasma chamber, wherein the surface is different than a surface of the substrate; igniting a plasma in the plasma chamber; exposing the surface to energy to cause the emission of negative ions from chemisorbed second gas species into the plasma; and processing the substrate in the plasma chamber using the plasma containing the negative ions.
Claim 18
Dependent Claim
30 words
The method of claim 15 further comprising: igniting the plasma by applying a pulsed RF signal to an electrode operably coupled to the plasma chamber to form a pulsed plasma.
Claim 19
Dependent Claim
37 words
The method of claim 15 further comprising: applying a pulsed voltage to the substrate that alternates the bias of the substrate between a negative bias voltage level and a less negative or a positive bias voltage level.
Claim 20
Dependent Claim
21 words
The method of claim 15 wherein: the exposing of the surface includes applying a time average negative potential on the surface.
Claim 21
Dependent Claim
51 words
The method of claim 16 , wherein: the exposing of the surface includes impacting the surface with radiation from the pulsed plasma to release negative ions of the gas species into the pulsed plasma and interacting the negative ions with a non-ionized portion of the processing gas to emit energized electrons.
Claim 22
Dependent Claim
18 words
The method of claim 19 , wherein the interacting includes neutralizing the negative ions to emit energized electrons.
Claim 23
Dependent Claim
16 words
The method of claim 20 further comprising: energizing a second plasma with the emitted energized electrons.
Claim 24
Dependent Claim
100 words
The method of claim 21 , further comprising: exposing the substrate to the second plasma; applying a pulsed DC bias to the substrate positioned on a substrate support in the plasma chamber; and periodically biasing the substrate positioned on the substrate support between first and second bias levels, the first bias level being more negative than the second bias level, wherein the substrate and the substrate support, when biased at the first bias level, attract mono-energetic positive ions from the plasma toward the substrate and are operable to enhance a selected chemical etch process at a surface of the substrate.
Claim 25
Dependent Claim
36 words
The method of claim 16 , further comprising: increasing an electron density of the pulsed plasma by emitting negative ions from a secondary electron source that are reactive to a non-ionized portion of the processing gas.
Claim 26
Dependent Claim
16 words
The method of claim 23 , further comprising: neutralizing the negative ions to emit energized electrons.
Claim 27
Dependent Claim
30 words
The method of claim 24 , further comprising: energizing a secondary plasma in a portion of the plasma chamber between the plasma and the substrate with the emitted energized electrons.
Claim 28
Dependent Claim
72 words
The method of claim 25 , further comprising: positioning the substrate on a substrate support and applying a pulsed DC bias to the substrate on the substrate support; and periodically biasing the substrate between first and second bias levels, the first bias level being more negative than the second bias level, wherein the substrate, when biased at the first bias level, attracts mono-energetic positive ions from the pulsed plasma toward the substrate.
Claim 29
Dependent Claim
98 words
The method of claim 15 , wherein: the chemisorbing the second gas species and the igniting of the plasma are carried out in a first plasma sub-chamber within the plasma chamber having the surface therein, the ignited plasma being a primary plasma, the negative ions increasing an electron density in the primary plasma by being neutralized in the primary plasma to thereby emit energized secondary electrons; and the processing of the substrate is carried out in a second plasma sub-chamber having the substrate therein by forming a secondary plasma in the second sub-chamber with the energized secondary electrons.
Claim 30
Dependent Claim
80 words
The method of claim 27 , wherein the substrate is positioned on a substrate holder in the second plasma sub-chamber, the method further comprising: applying a pulsed DC bias to the substrate positioned on the substrate holder; and periodically biasing the substrate between first and second bias levels, the first bias level being more negative than the second bias level, wherein the substrate, when biased at the first bias level, attracts mono-energetic positive ions from the plasma toward the substrate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2020-10-23 | 2021-04-24 | 2021-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2024-10-23 | 2025-04-24 | 2025-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2028-10-23 | 2029-04-24 | 2029-10-24 | $7700.00 | Pending Window |