US5320707A
Expired / Lapsed
US
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Dry etching method
Assignee: Hitachi Ltd
•
Filing: 1993-05-20
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Granted: 1994-06-14
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Expires: 2013-05-20
Abstract
Abstract Disclosed is a method of dry-etching a sample (e.g., a wafer) having an aluminum system film structure to be etched. Etching is performed in a plasma, under reduced pressure, the plasma being formed from a gas mixture containing a halogen system gas (e.g., Cl2, HBr, BCl3, etc.) and a ROH gas (e.g., CH3OH, C3H5OH, C5H7OH, CH3COOH, HOCH2CH2OH, etc.). By incorporating the ROH gas with the halogen system gas, in etching, e.g., an aluminum system film structure, etching can be performed with an accurate shape corresponding to a mask pattern, irrespective of the pattern density. Moreover, the aluminum system film structure can be etched at a uniform speed irrespective of the pattern density; and a selection ratio for etching the aluminum system film structure, as compared with etching material (e.g., organic resist) of the mask, is improved.
Inventors
- 👤 Tadamitsu Kanekiyo
- 👤 Hironobu Kawahara
- 👤 Yoshiaki Sato
- 👤 Kotaro Fujimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:33
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/242; H10P72/00; H10P72/04; H10P72/0451; H10P72/0452; C; C23; C23F; C23F4/00; H01; H01J; H01J37/00; H01J37/02; H01J37/18; H01J37/185; H01J37/32; H01J37/32009; H01J37/32192; H01J37/32431; H01J37/32733; H01J37/32743; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P70/00; H10P72/0402; H10P72/0418; H10P72/0421; H10P72/0454; H10P72/0468; H10P72/30; H10P72/33; H10P72/3304; H10P72/3306; H10P72/3308
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
70 words
A method of dry-etching a sample, comprising the steps of: providing a sample, to be dry-etched, in a plasma etching chamber, the sample including an aluminum system film structure to be dry-etched, as at least a portion of the sample to be dry-etched; and plasma etching the sample in a plasma formed from a gas mixture of a halogen system gas and a ROH gas, R being a carbon-containing chain.
Claim 2
Independent Claim
70 words
A method of dry-etching a sample, comprising the steps of: providing a sample, to be dry-etched, in a plasma etching chamber, the sample including an aluminum system film structure to be dry-etched, as at least a portion of the sample to be dry-etched; and plasma etching the sample in a plasma formed from a gas mixture of a halogen system gas and a ROH gas, R being a carbon-containing chain.
Claim 3
Dependent Claim
36 words
A method according to claim 1, where said halogen system gas is at least one halogen-containing gas selected from the group consisting of BCl 3 , Cl 2 , HBr, Br 2 and BBr 3 .
Claim 4
Dependent Claim
35 words
A method according to claim 2, wherein said ROH gas is at least one gas selected from the group consisting of CH 3 OH, C 3 H 5 OH and C 5 H 7 OH.
Claim 5
Dependent Claim
60 words
A method according to claim 3, wherein said aluminum system film structure is selected from the group consisting of a layer of aluminum, a layer of aluminum alloy, a multi-layer film including a layer of aluminum and a layer of a barrier metal, and a multi-layer film including a layer of aluminum alloy and a layer of a barrier metal.
Claim 6
Dependent Claim
31 words
A method according to claim 4, wherein the ROH gas is included in the gas mixture in a concentration of 5-15% by volume of the total volume of the gas mixture.
Claim 7
Dependent Claim
36 words
A method according to claim 5, wherein the sample, during the plasma etching thereof, has a mask on a surface thereof to be dry-etched, surface portions of the sample, not covered by the mask, being etched.
Claim 8
Dependent Claim
15 words
A method according to claim 6, wherein the mask is made of an organic resist.
Claim 9
Dependent Claim
20 words
A method according to claim 1, wherein, for ROH gas, R=C n H m , with n=1-3 inclusive, and m=2n±1.
Claim 10
Dependent Claim
26 words
A method according to claim 1, wherein the ROH gas is selected from the group consisting of CH 3 COOH and HOCH 2 CH 2 OH.
Claim 11
Dependent Claim
31 words
A method according to claim 1, wherein the ROH gas is included in the gas mixture in a concentration of 5-15% by volume of the total volume of the gas mixture.
Claim 12
Dependent Claim
36 words
A method according to claim 1, wherein the sample, during the plasma etching thereof, has a mask on a surface thereof to be dry-etched, surface portions of the sample, not covered by the mask, being etched.
Claim 13
Dependent Claim
15 words
A method according to claim 11, wherein the mask is made of an organic resist.
Claim 14
Dependent Claim
35 words
A method according to claim 1, wherein said ROH gas is at least one gas selected from the group consisting of CH 3 OH, C 3 H 5 OH and C 5 H 7 OH.
Claim 15
Dependent Claim
60 words
A method according to claim 1, wherein said aluminum system film structure is selected from the group consisting of a layer of aluminum, a layer of aluminum alloy, a multi-layer film including a layer of aluminum and a layer of a barrier metal, and a multi-layer film including a layer of aluminum alloy and a layer of a barrier metal.
Claim 16
Independent Claim
85 words
A method of dry-etching a sample, comprising the steps of: providing a sample, to be dry-etched, on a sample table in a plasma etching chamber, the sample including an aluminum system film structure, to be dry-etched, forming at least a part of the sample to be dry-etched; forming a plasma in the plasma chamber, from a gas mixture comprising a halogen system gas and a ROH gas, R being a carbon-containing chain, under a reduced pressure condition; and plasma etching the sample using said plasma.
Claim 17
Independent Claim
85 words
A method of dry-etching a sample, comprising the steps of: providing a sample, to be dry-etched, on a sample table in a plasma etching chamber, the sample including an aluminum system film structure, to be dry-etched, forming at least a part of the sample to be dry-etched; forming a plasma in the plasma chamber, from a gas mixture comprising a halogen system gas and a ROH gas, R being a carbon-containing chain, under a reduced pressure condition; and plasma etching the sample using said plasma.
Claim 18
Dependent Claim
39 words
A method according to claim 15, wherein during said plasma etching a high frequency electric power is applied to said sample table to cause a bias voltage, thereby to control incidence of ions, in the plasma, on the sample.
Claim 19
Dependent Claim
27 words
A method according to claim 16, wherein said plasma is formed by an action between (1) an electric field created by microwaves and (2) a magnetic field.
Claim 20
Dependent Claim
36 words
A method according to claim 17, where said halogen system gas is at least one halogen-containing gas selected from the group consisting of BCl 3 , Cl 2 , HBr, Br 2 and BBr 3 .
Claim 21
Dependent Claim
35 words
A method according to claim 18, wherein said ROH gas is at least one gas selected from the group consisting of CH 3 OH, C 3 H 5 OH and C 5 H 7 OH.
Claim 22
Dependent Claim
60 words
A method according to claim 19, wherein said aluminum system film structure is selected from the group consisting of a layer of aluminum, a layer of aluminum alloy, a multi-layer film including a layer of aluminum and a layer of a barrier metal, and a multi-layer film including a layer of aluminum alloy and a layer of a barrier metal.
Claim 23
Dependent Claim
31 words
A method according to claim 20, wherein the ROH gas is included in the gas mixture in a concentration of 5-15% by volume of the total volume of the gas mixture.
Claim 24
Dependent Claim
36 words
A method according to claim 21, wherein the sample, during the plasma etching thereof, has a mask on a surface thereof to be dry-etched, surface portions of the sample, not covered by the mask, being etched.
Claim 25
Dependent Claim
15 words
A method according to claim 22, wherein the mask is made of an organic resist.
Claim 26
Dependent Claim
32 words
A method according to claim 20, wherein the reduced pressure condition is 5-16 mTorr, a microwave power forming the microwaves is 200-400 mA, and the bias voltage is -40 to -50 V.
Claim 27
Dependent Claim
22 words
A method according to claim 20, wherein said gas mixture includes BCl 3 , Cl 2 and C 3 H 5 OH.
Claim 28
Dependent Claim
69 words
A method according to claim 25, wherein said sample is either an 8 inch wafer or a 6 inch wafer, and wherein a gas supply amount of the gas mixture supplied into the plasma etching chamber during dry etching of the 8 inch wafer is greater than a gas supply amount of the gas mixture supplied into the plasma etching chamber during dry etching of the 6 inch wafer.
Claim 29
Dependent Claim
32 words
A method according to claim 17, wherein the reduced pressure condition is 5-16 mTorr, a microwave power forming the microwaves is 200-400 mA, and the bias voltage is -40 to -50 V.
Claim 30
Dependent Claim
22 words
A method according to claim 27, wherein said gas mixture includes BCl 3 , Cl 2 and C 3 H 5 OH.
Claim 31
Dependent Claim
67 words
A method according to claim 28, wherein said sample is either an 8 inch wafer or a 6 inch wafer, and where supply amount of the gas mixture supplied into the plasma etching chamber during dry etching of the 8 inch wafer is greater than a gas supply amount of the gas mixture supplied into the plasma etching chamber during dry etching of the 6 inch wafer.
Claim 32
Independent Claim
74 words
A method of dry-etching a sample, comprising the steps of: providing a sample, to be dry-etched, in a plasma etching chamber, the sample including an aluminum system film structure, to be dry-etched, as at least a portion of the sample to be dry-etched; and plasma etching the sample in a plasma formed from a gas mixture of CH 3 OH and Cl 2 , the plasma acting to etch the aluminum system film structure.
Claim 33
Independent Claim
74 words
A method of dry-etching a sample, comprising the steps of: providing a sample, to be dry-etched, in a plasma etching chamber, the sample including an aluminum system film structure, to be dry-etched, as at least a portion of the sample to be dry-etched; and plasma etching the sample in a plasma formed from a gas mixture of CH 3 OH and Cl 2 , the plasma acting to etch the aluminum system film structure.
Claim 34
Dependent Claim
15 words
A method according to claim 30, wherein the plasma etching is performed under reduced pressure.
Claim 35
Dependent Claim
25 words
A method according to claim 31, wherein said aluminum system film structure is a film of aluminum or a film of an alloy of aluminum.
Claim 36
Dependent Claim
36 words
A method according to claim 32, wherein the sample, during the plasma etching thereof, has a mask on a surface thereof to be dry-etched, surface portions of the sample, not covered by the mask, being etched.
Claim 37
Dependent Claim
15 words
A method according to claim 33, wherein the mask is made of an organic resist.
Claim 38
Dependent Claim
33 words
A method according to claim 34, wherein the CH 3 OH gas is included in the gas mixture in a concentration of 5-15% by volume of the total volume of the gas mixture.
References Cited (Backward Citations)
US4505782A
Cited
JPS60234325A
Cited
JPH0383337A
Cited
JPH0415919A
Cited
JPH0492429A
Cited
JPH04147621A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-06-13 | 1997-12-13 | 1998-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-13 | 2001-12-13 | 2002-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-13 | 2005-12-13 | 2006-06-14 | $7700.00 | Window Closed / Lapsed |