US5869402A
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Plasma generating and processing method and apparatus thereof
Assignee: Panasonic Holdings Corp
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Filing: 1995-05-10
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Granted: 1999-02-09
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Expires: 2015-05-10
Abstract
Abstract A reactive gas is introduced into a vacuum chamber by a gas controller so that a plasma is generated in a plasma generation region. Subsequently, high-frequency power from a high-frequency power source is applied to a sample stage in the vacuum chamber so that ions in the plasma are made incident upon the sample stage, thereby performing dry etching with respect to a sample on the sample stage. In main etching, a value of (pressure of reactive gas)/(frequency of high-frequency power) is reduced so as to reduce a scattering probability, which is the probability of ions being scattered in collision with neutral particles in a sheath region, thereby increasing the energy of ion fluxes and making the incidence directions of the ion fluxes perpendicular to a surface of the sample stage. In overetching, the value of (pressure of reactive gas)/(frequency of high-frequency power) is increased so as to increase the above scattering probability, thereby reducing the energy of the ion fluxes and tilting the incidence directions of the ion fluxes from a perpendicular to the surface of the sample stage.
Inventors
- 👤 Kenji Harafuji
- 👤 Masafumi Kubota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:35
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H01; H01J; H01J37/00; H01J37/32; H05; H05H; H05H1/00; H10P50/24; H10P50/242; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268; H10P72/00; H10P72/04; H10P72/0402; H10P72/0418; H10P72/0421
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
222 words
A plasma generating and processing method comprising: a plasma generating step of introducing a gas into a vacuum chamber and generating a plasma in a plasma generation region; and a plasma processing step of applying high-frequency power to a sample stage in the vacuum chamber so that ions in the plasma are made incident upon said sample stage and perform dry etching process on a sample on the sample stage with a scattering probability, which is the probability of said ions being scattered in collision with neutral particles in a sheath region on the side of said sample stage, a value of the scattering probability being determined depending on a value of (pressure of gas)/(frequency of high-frequency power), wherein said plasma processing step comprises; the step of setting the value of (pressure of gas)/(frequency of high-frequency power) at a low value to obtain a low scattering probability in main etching, thereby increasing the energy of said ion fluxes and making the incidence directions of said ion fluxes perpendicular to a surface of said sample stage, and then increasing the value of (pressure of gas)/(frequency of high-frequency power) to obtain a high scattering probability in overetching, thereby reducing the energy of said ion fluxes and tilting the incidence directions of said ion fluxes from a perpendicular to the surface of the sample stage.
Claim 2
Dependent Claim
222 words
A plasma generating and processing method comprising: a plasma generating step of introducing a gas into a vacuum chamber and generating a plasma in a plasma generation region; and a plasma processing step of applying high-frequency power to a sample stage in the vacuum chamber so that ions in the plasma are made incident upon said sample stage and perform dry etching process on a sample on the sample stage with a scattering probability, which is the probability of said ions being scattered in collision with neutral particles in a sheath region on the side of said sample stage, a value of the scattering probability being determined depending on a value of (pressure of gas)/(frequency of high-frequency power), wherein said plasma processing step comprises; the step of setting the value of (pressure of gas)/(frequency of high-frequency power) at a low value to obtain a low scattering probability in main etching, thereby increasing the energy of said ion fluxes and making the incidence directions of said ion fluxes perpendicular to a surface of said sample stage, and then increasing the value of (pressure of gas)/(frequency of high-frequency power) to obtain a high scattering probability in overetching, thereby reducing the energy of said ion fluxes and tilting the incidence directions of said ion fluxes from a perpendicular to the surface of the sample stage.
Claim 3
Dependent Claim
80 words
A plasma generating and processing method according to claim 1, wherein in said plasma processing step, the value of (pressure of gas)/(frequency of high-frequency power) is set at a low value in main etching and then increased in overetching, by: setting the frequency of said high-frequency power at the same value both in main etching and in overetching; setting the pressure of said gas at a low value in main etching; and increasing the pressure of said gas in overetching.
Claim 4
Dependent Claim
81 words
A plasma generating and processing method according to claim 1, wherein in said plasma processing step, the value of (pressure of gas)/(frequency of high-frequency power) is set at a low value in main etching and then increased in overetching, by: setting the pressure of said gas at the same value both in main etching and in overetching; setting the frequency of said high-frequency power at a high value in main etching; and reducing the frequency of said high-frequency power in overetching.
Claim 5
Dependent Claim
59 words
A plasma generating and processing method according to claim 3, wherein in said plasma processing step, the frequency of said high-frequency power in overetching is set at a value that is about one fifth of the frequency of said high-frequency power in main etching or more and does not exceed the frequency of said high-frequency power in main etching.
Claim 6
Dependent Claim
82 words
A plasma generating and processing method according to claim 1, wherein in said plasma processing step, the value of (pressure of gas)/(frequency of high-frequency power) is set at a low value in main etching and then increased in overetching, by: setting the pressure of said gas at a low value and setting the frequency of said high-frequency power at a high value in main etching; and increasing the pressure of said gas and reducing the frequency of said high-frequency power in overetching.
Claim 7
Dependent Claim
59 words
A plasma generating and processing method according to claim 5, wherein in said plasma processing step, the frequency of said high-frequency power in overetching is set at a value that is about one fifth of the frequency of said high-frequency power in main etching or more and does not exceed the frequency of said high-frequency power in main etching.
Claim 8
Dependent Claim
59 words
A plasma generating and processing method according to claim 1, wherein in said plasma processing step, the value of (pressure of gas)/(frequency of high-frequency power) that is set at a low value in main etching is increased in overetching so that the high scattering probability in overetching becomes 1.5 times the low scattering probability in main etching or higher.
Claim 9
Dependent Claim
66 words
A plasma generating and processing method according to claim 1, wherein in said plasma processing step, if the scattering probability is defined as (length of sheath region on sample-stage side)/(mean free path of ions in sheath region on sample-stage side), the value of (pressure of gas)/(frequency of high-frequency power) is set so that the value of the scattering probability becomes 6 or less in main etching.
Claim 10
Dependent Claim
65 words
A plasma generating and processing method according to claim 1, wherein in said plasma processing step, if the scattering probability is defined as (length of sheath region on sample-stage side)/(mean free path of ions in sheath region on sample-stage side), the value of (pressure of gas)/(frequency of high-frequency power) is set so that the value of the scattering probability becomes 6 or more in overetching.
Claim 11
Dependent Claim
49 words
A plasma generating and processing method according to claim 1, wherein in said plasma processing step, when a terminate signal was outputted from a terminal detector which outputs the terminate signal upon detecting the termination of main etching, the value of (pressure of gas)/(frequency of high-frequency power) is increased.
Claim 12
Dependent Claim
34 words
A plasma generating and processing method according to claim 1, wherein in said plasma processing steps the value of (pressure of gas)/(frequency of high-frequency power) is increased when a predetermined period of time elapsed.
Claim 13
Dependent Claim
37 words
A plasma generating and processing method according to claim 1, wherein in said plasma processing step, the frequency of said high-frequency power in main etching is set at a value equal to or higher than 10 MHz.
Claim 14
Dependent Claim
36 words
A plasma generating and processing method according to claim 1, wherein in said plasma processing step, the pressure of said gas in main etching is set at a value equal to or lower than 20 Pa.
Claim 15
Dependent Claim
224 words
A plasma generating and processing method comprising: a plasma generating step of introducing a gas into a vacuum chamber and generating a plasma in a plasma generation region; and a plasma processing step of applying high-frequency power to a sample stage in the vacuum chamber so that ions in the plasma are made incident upon said sample stage and perform thin-film forming process on a sample on the sample stage with a scattering probability which is the probability of said ions being scattered in collision with neutral particles in a sheath region on the side of said sample stage, a value of the scattering probability being determined depending on a value of (pressure of gas)/(frequency of high-frequency power), wherein said plasma processing step comprises the step of setting the value of (pressure of gas)/(frequency of high-frequency power) at a high value to obtain a high scattering probability in main thin-film formation, thereby reducing the energy of said ion fluxes and tilting the incidence directions of said ion fluxes from a perpendicular to a surface of the sample stage, and then reducing the value of (pressure of gas)/(frequency of high-frequency power) to obtain a low scattering probability in step-coverage mending, thereby increasing the energy of said ion fluxes and making the incidence directions of said ion fluxes perpendicular to the surface of said sample state.
Claim 16
Dependent Claim
224 words
A plasma generating and processing method comprising: a plasma generating step of introducing a gas into a vacuum chamber and generating a plasma in a plasma generation region; and a plasma processing step of applying high-frequency power to a sample stage in the vacuum chamber so that ions in the plasma are made incident upon said sample stage and perform thin-film forming process on a sample on the sample stage with a scattering probability which is the probability of said ions being scattered in collision with neutral particles in a sheath region on the side of said sample stage, a value of the scattering probability being determined depending on a value of (pressure of gas)/(frequency of high-frequency power), wherein said plasma processing step comprises the step of setting the value of (pressure of gas)/(frequency of high-frequency power) at a high value to obtain a high scattering probability in main thin-film formation, thereby reducing the energy of said ion fluxes and tilting the incidence directions of said ion fluxes from a perpendicular to a surface of the sample stage, and then reducing the value of (pressure of gas)/(frequency of high-frequency power) to obtain a low scattering probability in step-coverage mending, thereby increasing the energy of said ion fluxes and making the incidence directions of said ion fluxes perpendicular to the surface of said sample state.
Claim 17
Dependent Claim
86 words
A plasma generating and processing method according to claim 14, wherein in said plasma processing step, the value of (pressure of gas)/(frequency of high-frequency power) is set at a high value in main thin-film formation and then reduced in step-coverage mending, by: setting the frequency of said high-frequency power at the same value both in main thin-film formation and in step-coverage mending; setting the pressure of said gas at a high value in main thin-film formation; and reducing the pressure of said gas in step-coverage mending.
Claim 18
Dependent Claim
87 words
A plasma generating and processing method according to claim 14, wherein in said plasma processing step, the value of (pressure of gas)/(frequency of high-frequency power) is set at a high value in main thin-film formation and then reduced in step-coverage mending, by: setting the pressure of said gas at the same value both in main thin-film formation and in step-coverage mending; setting the frequency of said high-frequency power at a low value in main thin-film formation; and increasing the frequency of said high-frequency power in step-coverage mending.
Claim 19
Dependent Claim
48 words
A plasma generating and processing method according to claim 16, wherein in said plasma processing step, the frequency of said high-frequency power in step-coverage mending is set at a value equal to or less than about five times the frequency of said high-frequency power in main thin-film formation.
Claim 20
Dependent Claim
87 words
A plasma generating and processing method according to claim 14, wherein in said plasma processing step, the value of (pressure of gas)/(frequency of high-frequency power) is set at a high value in main thin-film formation and then reduced in step-coverage mending, by: setting the pressure of said gas at a high value and setting the frequency of said high-frequency power at a low value in main thin-film formation and then reducing the pressure of said gas and increasing the frequency of said high-frequency power in step-coverage mending.
Claim 21
Dependent Claim
48 words
A plasma generating and processing method according to claim 18, wherein in said plasma processing step, the frequency of said high-frequency power in step-coverage mending is set at a value equal to or less than about five times the frequency of said high-frequency power in main thin-film formation.
Claim 22
Dependent Claim
63 words
A plasma generating and processing method according to claim 14, wherein in said plasma processing step, the value of (pressure of gas)/(frequency of high-frequency power) that is set at a high value in main thin-film formation is reduced in step-coverage mending so that the high scattering probability in main thin-film formation becomes 1.5 times the low scattering probability in step-coverage mending or more.
Claim 23
Dependent Claim
67 words
A plasma generating and processing method according to claim 14, wherein in said plasma processing step, if the scattering probability is defined as (length of sheath region on sample-stage side)/(mean free path of ions in sheath region on sample-stage side), the value of (pressure of gas)/(frequency of high-frequency power) is set so that the value of the scattering probability becomes 6 or more in main thin-film formation.
Claim 24
Dependent Claim
66 words
A plasma generating and processing method according to claim 14, wherein in said plasma processing step, if the scattering probability is defined as (length of sheath region on sample-stage side)/(mean free path of ions in sheath region on sample-stage side), the value of (pressure of gas)/(frequency of high-frequency power) is set so that the value of the scattering probability becomes 6 or less in step-coverage mending.
Claim 25
Dependent Claim
34 words
A plasma generating and processing method according to claim 14, wherein in said plasma processing step, the value of (pressure of gas)/(frequency of high-frequency power) is reduced when a predetermined period of time elapsed.
Claim 26
Dependent Claim
34 words
A plasma generating and processing method according to claim 14, wherein in said plasma processing step, the frequency of said high-frequency power is set at a value equal to or higher than 10 MHz.
Claim 27
Dependent Claim
33 words
A plasma generating and processing method according to claim 14, wherein in said plasma processing step, the pressure of said gas is set at a value equal to or lower than 20 Pa.
References Cited (Backward Citations)
US5415718A
Cited
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