Patent US5698070A successfully refreshed from Google Patents.
US5698070A
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US
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Method of etching film formed on semiconductor wafer
Assignee: Tokyo Electron Ltd
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Filing: 1993-12-30
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Granted: 1997-12-16
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Expires: 2013-12-30
Abstract
Abstract A method of etching oxide film on a semiconductor wafer comprising pushing the wafer against the top of lower electrode while facing it to an upper electrode, decompressing to exhaust a chamber, forming electric field between the wafer and the upper electrode under decompressed state and generating the gas plasma of process gas while supplying the process gas to an oxide-film-formed surface of the wafer through the upper electrode, introducing auxiliary gas to the peripheral portion of the wafer when the gas plasma of process gas is acting on the wafer, and controlling the etching reaction of the gas plasma relative to the peripheral portion of the wafer by auxiliary gas.
Inventors
- 👤 Yoshihisa Hirano
- 👤 Yoshifumi Tahara
- 👤 Hiroshi Nishikawa
- 👤 Isahiro Hasegawa
- 👤 Keiji Horioka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 16:47
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/04; H10P72/0431; H10P72/0434; H01; H01J; H01J37/00; H01J37/32; H01J37/32431; H01J37/3244; H01J2237/00; H01J2237/20; H01J2237/2001
Claims Analysis
Total Claims: 49
Claim 1
Independent Claim
273 words
A method of etching a film formed on a surface of a semiconductor wafer, comprising: providing a first gas source and a second gas source, which both communicate with a chamber, and a valve arranged on a passageway communicating said first gas source and said second gas source; holding a wafer on a lower electrode in the chamber by holder means such that the wafer faces an upper electrode; exhausting the chamber to reduce an inner pressure of the chamber; forming an electric field under reduced pressure between the wafer and the upper electrode while supplying a process gas from said first gas source through the upper electrode toward the wafer to form a gas plasma of the process gas; and simultaneously introducing an auxiliary gas differing in composition from the process gas, from said second gas source by closing said valve, or from both said first and second gas sources by opening said valve, into a micro-clearance between the wafer and the lower electrode and allowing said auxiliary gas to leak into the chamber through said micro-clearance, while the gas plasma of the process gas is acting on the wafer thereby allowing an etching reaction performed by the gas plasma of the process gas in a peripheral portion of the wafer to be controlled by the auxiliary gas; wherein 1) the process gas comprises a gas not present in the auxiliary gas of the auxiliary gas comprises a gas not present in the process gas or 2) the auxiliary gas comprises a gas not present in the process gas and the process gas comprises a gas not present in the auxiliary gas.
Claim 2
Independent Claim
273 words
A method of etching a film formed on a surface of a semiconductor wafer, comprising: providing a first gas source and a second gas source, which both communicate with a chamber, and a valve arranged on a passageway communicating said first gas source and said second gas source; holding a wafer on a lower electrode in the chamber by holder means such that the wafer faces an upper electrode; exhausting the chamber to reduce an inner pressure of the chamber; forming an electric field under reduced pressure between the wafer and the upper electrode while supplying a process gas from said first gas source through the upper electrode toward the wafer to form a gas plasma of the process gas; and simultaneously introducing an auxiliary gas differing in composition from the process gas, from said second gas source by closing said valve, or from both said first and second gas sources by opening said valve, into a micro-clearance between the wafer and the lower electrode and allowing said auxiliary gas to leak into the chamber through said micro-clearance, while the gas plasma of the process gas is acting on the wafer thereby allowing an etching reaction performed by the gas plasma of the process gas in a peripheral portion of the wafer to be controlled by the auxiliary gas; wherein 1) the process gas comprises a gas not present in the auxiliary gas of the auxiliary gas comprises a gas not present in the process gas or 2) the auxiliary gas comprises a gas not present in the process gas and the process gas comprises a gas not present in the auxiliary gas.
Claim 3
Dependent Claim
49 words
The etching method according to claim 1, wherein internal pressure in the chamber is made lower than 1 Torr and the pressure of the auxiliary gas introduced into the micro-clearance between the wafer and the lower electrode is controlled to be in a range of 3 to 20 Torr.
Claim 4
Dependent Claim
18 words
The etching method according to claim 2, wherein the pressure of the auxiliary gas introduced is kept constant.
Claim 5
Dependent Claim
19 words
The etching method according to claim 2, wherein the pressure of the auxiliary gas introduced is increased and decreased.
Claim 6
Dependent Claim
32 words
The etching method according to claim 1, wherein a groove is formed in the top of the lower electrode and the auxiliary gas is introduced into this groove of the lower electrode.
Claim 7
Dependent Claim
16 words
The etching method according to claim 1, wherein the introduction of the auxiliary gas is intermittent.
Claim 8
Dependent Claim
22 words
The etching method according to claim 1, wherein the auxiliary gas is pre-heated or -cooled to match the temperature of the wafer.
Claim 9
Dependent Claim
33 words
The etching method according to claim 1, wherein an amount of the auxiliary gas leaked from the micro-clearance into the chamber is controlled to be in a range of 0.1 to 50 SCCM.
Claim 10
Dependent Claim
37 words
The etching method according to claim 1, wherein a clamp ring is used as holder means and the wafer clamping force of it is controlled to be in a range of 1 to 8 kg/cm 2 .
Claim 11
Dependent Claim
38 words
The etching method according to claim 1, wherein said auxiliary gas contains a halogen element and at least one member selected from the group consisting of a second halogen element, carbon, hydrogen, boron, nitrogen, sulfur, phosphorus and oxygen.
Claim 12
Dependent Claim
77 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of saturated carbon fluorides, saturated carbon chlorides, saturated carbon bromides, saturated carbon iodides, saturated mixed carbon halides, unsaturated mixed carbon halides, saturated mixed hydrocarbons, unsaturated mixed hydrocarbons unsaturated carbon halides, saturated cyclic carbon halides, unsaturated cyclic carbon halides, halogen gas, interhalogen compounds, hydrogen halides, boron halides, boron hydrides, halogenoborohydrides, nitrogen halides, sulfur halides, silane halides and phosphine halides.
Claim 13
Dependent Claim
164 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of HCl, HBr, HI, SF 6 , CF 4 , F 2 , Cl 2 , Br 2 , I 2 , At 2 , Cl 3 F, ICl 3 , ClF, ICl, BrF, BrF 3 , BrF 5 , IF 5 , IF 7 , CBrF 3 , CFBr 3 , C 2 ClF 5 , CClF 3 , C 2 BrF 3 , C 2 FCl 3 , CHF 3 , CHBrF 2 , CHBr 3 , CH 2 Br 2 , CHCl 3 , C 2 HF 2 Br 3 , C 2 HFCl 3 , C 2 H 2 FCl, C 2 F 4 , C 3 F 6 , C 4 F 8 , C 2 F 2 , C 3 F 4 , C 4 F 6 , PCl 3 , PCl 5 and P 2 Cl 4 .
Claim 14
Dependent Claim
33 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of saturated hydrocarbons, unsaturated hydrocarbons, saturated cyclic hydrocarbons, unsaturated cyclic hydrocarbons and aromatic compounds.
Claim 15
Dependent Claim
44 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of C 2 H 4 , C 3 H 6 , C 2 H 2 , C 3 H 4 , toluene, xylene and phenol.
Claim 16
Dependent Claim
42 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of air, N 2 , O 2 , O 3 , H 2 O, H 2 O 2 , and H 2 .
Claim 17
Dependent Claim
15 words
The etching method according to claim 1, wherein inert gas is used as auxiliary gas.
Claim 18
Dependent Claim
27 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of He, Ne, Ar, Kr, Xe and Rn.
Claim 19
Dependent Claim
34 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of AsH 3 , R-AsH 2 , R 2 -AsH and R 3 -As, R=alkyl.
Claim 20
Dependent Claim
15 words
The etching method according to claim 1, wherein Boron hydride is used as auxiliary gas.
Claim 21
Dependent Claim
14 words
The etching method according to claim 1, wherein silane is used as auxiliary gas.
Claim 22
Dependent Claim
38 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of SiH 4 , Si 2 H 6 , Si 3 H 8 and Si 4 H 10 .
Claim 23
Dependent Claim
23 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of alcohols and polyols.
Claim 24
Dependent Claim
23 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of ethers and thioethers.
Claim 25
Dependent Claim
14 words
The etching method according to claim 1, wherein ketone is used as auxiliary gas.
Claim 26
Dependent Claim
44 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of acetone, dimethyl ketone, methyl ethyl ketone (MEK), pinacoline, unsaturated mesythyloxide, acetophenone, benzophenone, diketones, quinones, cyclic ketones such as cyclohexanone, hydroxylketone, ketonic acid and quinols.
Claim 27
Dependent Claim
28 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of carbonyl sulfide (COS) and phosgene (COCl 2 ).
Claim 28
Dependent Claim
29 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of formic acid (HCOOH) and acetic acid (CH 3 COOH).
Claim 29
Dependent Claim
18 words
The etching method according to claim 1, wherein thionyl bromide (SOBr 2 ) is used as auxiliary gas.
Claim 30
Dependent Claim
18 words
The etching method according to claim 1, wherein phospholyl such as POCl 3 is used as auxiliary gas.
Claim 31
Dependent Claim
15 words
The etching method according to claim 1, wherein phosphorous hidride is used as auxiliary gas.
Claim 32
Dependent Claim
30 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of phosphine (PH 3 ) and alkyl phosphine (R-PH 2 ).
Claim 33
Dependent Claim
24 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of sulfuric and nitric acids.
Claim 34
Dependent Claim
14 words
The etching method according to claim 1, wherein ammonia is used as auxiliary gas.
Claim 35
Dependent Claim
50 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of N 2 O, NO, NO 2 , NO 3 , N 2 O 3 , N 2 O 4 , N 2 O 5 and N 2 O 6 .
Claim 36
Dependent Claim
56 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of CS 2 , H 2 S, N 2 S 2 , N 4 S 4 , As 4 S 4 , As 2 S 3 , P 4 S 7 and P 2 S 5 .
Claim 37
Dependent Claim
43 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of SO, SO 2 , SO 3 , S 2 O, S 2 O 3 , S 2 O 7 and SO 4 .
Claim 38
Dependent Claim
15 words
The etching method according to claim 1, wherein phosphoric acid is used as auxiliary gas.
Claim 39
Dependent Claim
33 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of OF 2 , O 2 F 2 and O 3 F 2 .
Claim 40
Dependent Claim
43 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of Cl 2 O, ClO, ClO 2 , ClO 3 , Cl 2 O 6 , Cl 2 O 7 and ClO 4 .
Claim 41
Dependent Claim
39 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of Br 2 O, BrO 2 , BrO 3 , Br 3 O 8 and Br 3 O 7 .
Claim 42
Dependent Claim
35 words
The etching method according to claim 1, wherein said auxiliary gas is a member selected from the group consisting of As 2 O 3 , As 2 O 5 and As 2 O 4 .
Claim 43
Dependent Claim
15 words
The etching method according to claim 1, wherein cyanogen fluoride is used as auxiliary gas.
Claim 44
Dependent Claim
60 words
The etching method according to claim 1, wherein said film is formed of at least one of thermal SiO 2 , CVD-SiO 2 , PSG, BPSG, BSG, AsSG, SiO 2 -SixNy-SiO 2 (ONO), PbO.SiO 2 , PbO.Al 2 O 3 .SiO 2 , PbO.B 2 O 3 .SiO 2 , SiOxNy, SiON, Ta 2 O 5 and TiO 2 .
Claim 45
Dependent Claim
46 words
The etching method according to claim 1, further comprising the steps of: providing means for reserving the auxiliary gas; and enhancing the response of the pressure of the supplied gas to the chamber by making an internal circulation of the auxiliary gas in gas reserving means.
Claim 46
Dependent Claim
257 words
The etching method according to claim 1, wherein said auxiliary gas is selected from the group consisting of saturated hydrocarbons, unsaturated hydrocarbons, saturated cyclic hydrocarbons, unsaturated cyclic hydrocarbons, aromatic compounds, air, N 2 , O 2 , O 3 , H 2 O, H 2 O 2 , H 2 , CO, CO 2 , ASH 3 , R-AsH 2 , R 2 -AsH, R 3 -As, R-alkyl group boron hydrides, silanes, alcohols, polyols, ethers, thioethers, ketones, carbonyl sulfide, phosgene, formic acid, acetic acid, thionyl bromide, phospholyl, phosphorous hydrides, sulfuric acid, nitric acid, ammonia, N 2 O, NO, NO 2 , NO 3 , N 2 O 3 , N 2 O 4 , N 2 O 5 , N 2 O 6 , CS 2 , H 2 S, N 2 S 2 , N 4 S 4 , As 4 S 4 , As 2 S 3 , P 4 S 7 , P 2 S 5 , SO, SO 2 , SO 3 , S 2 O, S 2 O 3 , S 2 O 7 , SO 4 , phosphoric acids, OF 2 , O 2 F 2 , O 3 F 2 , Cl 2 O, ClO, ClO 2 , Cl 3 , Cl 2 O 6 , Cl 2 O 7 , ClO 4 , Br 2 O, BrO 2 , BrO 3 , Br 3 O 8 , Br 3 O 7 , As 2 O 3 , As 2 O 5 , As 2 O 4 and cyanogen fluoride.
Claim 47
Independent Claim
275 words
A method of etching a film formed on a surface of a semiconductor wafer, comprising: providing a first gas source and a second gas source, which both communicate with a chamber, and a valve arranged on a passageway communicating said first gas source and said second gas source; holding a wafer on a lower electrode in the chamber by an electrostatic chuck such that the wafer faces an upper electrode; exhausting the chamber to reduce an inner pressure of the chamber; forming an electric field under the reduced pressure between the wafer and the upper electrode while supplying a process gas from said first gas source, through the upper electrode toward the wafer to form a gas plasma of the process gas; and simultaneously introducing an auxiliary gas differing in composition from the process gas, from said second gas source by closing said valve, or from both said first and second gas sources by opening said valve, into a micro-clearance between the wafer and the lower electrode and allowing said auxiliary gas to leak into the chamber through said micro-clearance, while the gas plasma of the process gas is acting on the wafer, thereby allowing an etching reaction performed by the gas plasma of the process gas in a peripheral portion of the wafer to be controlled by the auxiliary gas; wherein 1) the process gas comprises a gas not present in the auxiliary gas or the auxiliary gas comprises a gas not present in the process gas or 2) the auxiliary gas comprises a gas not present in the process gas and the process gas comprises a gas not present in the auxiliary gas.
Claim 48
Independent Claim
275 words
A method of etching a film formed on a surface of a semiconductor wafer, comprising: providing a first gas source and a second gas source, which both communicate with a chamber, and a valve arranged on a passageway communicating said first gas source and said second gas source; holding a wafer on a lower electrode in the chamber by an electrostatic chuck such that the wafer faces an upper electrode; exhausting the chamber to reduce an inner pressure of the chamber; forming an electric field under the reduced pressure between the wafer and the upper electrode while supplying a process gas from said first gas source, through the upper electrode toward the wafer to form a gas plasma of the process gas; and simultaneously introducing an auxiliary gas differing in composition from the process gas, from said second gas source by closing said valve, or from both said first and second gas sources by opening said valve, into a micro-clearance between the wafer and the lower electrode and allowing said auxiliary gas to leak into the chamber through said micro-clearance, while the gas plasma of the process gas is acting on the wafer, thereby allowing an etching reaction performed by the gas plasma of the process gas in a peripheral portion of the wafer to be controlled by the auxiliary gas; wherein 1) the process gas comprises a gas not present in the auxiliary gas or the auxiliary gas comprises a gas not present in the process gas or 2) the auxiliary gas comprises a gas not present in the process gas and the process gas comprises a gas not present in the auxiliary gas.
Claim 49
Dependent Claim
29 words
The etching method according to claim 46, wherein a voltage applied to said electrostatic chuck is controlled to fall within a range of between 1 kV and 3 kV.
References Cited (Backward Citations)
US4680061A
Cited
US4909314A
Cited
US5024747A
Cited
US4565601A
Cited
JPS60136314A
Cited
US4661228A
Cited
US4931135A
Cited
DE3833386A1
Cited
US5147493A
Cited
US5238499A
Cited
US5147497A
Cited
US5221403A
Cited
US5356515A
Cited
US5415728A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2000-12-15 | 2001-06-16 | 2001-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-12-15 | 2005-06-16 | 2005-12-16 | $3760.00 | Window Closed / Lapsed |
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