EP0702391A2
Expired / Lapsed
EP
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Etch processing and plasma reactor for performing same
Assignee: Applied Materials Inc
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Filing: 1995-09-07
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Granted: —
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Expires: 2015-09-07
Abstract
Abstract The plasma source power frequency in a plasma etch reactor is reduced to a low RF frequency such as about 2 MHz. It is a discovery of this invention that at this low frequency, capacitive coupling from the plasma power source is reduced, and the plasma source power level may be increased beyond 750 Watts to reduce capacitive coupling and provide a high density inductively coupled plasma without appreciably increasing the ion bombardment energy. Moreover, under these conditions the etchant (e.g., chlorine) concentration in the plasma may be increased to about 80 percent without decreasing etch uniformity to provide a very high metal alloy etch rate with complete residue removal, no profile microloading, and no etch rate microloading, the process being applicable over a wide window of metal alloy compositions.
Inventors
- 👤 Diana Xiaobing Ma
- 👤 Gerald Z. Yin
- 👤 Hiroji Hanawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 04:32
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32009; H01J37/32082; H01J37/321; H01J37/3211; H01J37/32431; H01J37/32715; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/71; H10P72/00; H10P72/04; H10P72/0402; H10P72/0418; H10P72/0421
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
77 words
An etch process, especially for etching a conductive film on a semiconductor wafer in a plasma reactor, having an inductor coil for irradiating said reactor with RF source power and a wafer pedestal for supporting said wafer in said reactor, said etch process comprising the steps of: applying RF power in excess of 750 Watts at an RF frequency about or less than 6 MHz to said inductor coil; and introducing a gas into said plasma reactor.
Claim 2
Dependent Claim
29 words
The etch process according to claim 1, wherein the introduced gas comprises one or more etchant species for etching said conductive film constituting greater than 50% of said gas.
Claim 3
Dependent Claim
27 words
The etch process according to any one of the preceding claims further comprising applying a bias RF power at greater than 6 MHz to said wafer pedestal.
Claim 4
Dependent Claim
21 words
The etch process according to any one of the preceding claims wherein said source power is in excess of 1000 Watts.
Claim 5
Dependent Claim
19 words
The etch process according to any one of the preceding claims wherein said RF frequency is about 2.0 MHz.
Claim 6
Dependent Claim
24 words
The etch process according to any one of the preceding claims wherein said etchant species constitutes about or greater than 70% of said gas.
Claim 7
Dependent Claim
21 words
The etch process according to any one of the preceding claims wherein said etchant species constitutes about 80% of said gas.
Claim 8
Dependent Claim
23 words
The etch process according to any one of claims 1 to 6 wherein said etchant species constitutes greater than 80% of said gas.
Claim 9
Dependent Claim
39 words
The etch process according to any one of the preceding claims wherein said applying and introducing steps are preceded by a step of preliminarily defining features on a top thin film layer of said work piece to be etched.
Claim 10
Dependent Claim
41 words
The etch process of Claim 9 wherein said defining step comprises depositing photoresist over areas of said top thin film layer which are not to be etched, said photoresist comprising a material which is resistant to attack by said etchant species.
Claim 11
Dependent Claim
88 words
A plasma reactor, especially for etching a conductive film on a semiconductive wafer (45), comprising: a reactor vacuum chamber (10); a coil inductor (20) for irradiating said chamber (10) with plasma source RF power; a pedestal (50) inside said vacuum chamber (10) for supporting said wafer (45); means (25,30) for applying a plasma source powder in excess of 750 Watts at an RF frequency about or less than 6 MHz to said coil inductor; and a gas injection devise (35) for introducing a gas into said plasma reactor.
Claim 12
Dependent Claim
36 words
The plasma reactor according to claim 11, further comprising means (55,60) for applying a plasma bias power which is adapted for applying a bias power RF frequency of at least 1 MHz to said pedestal (50).
Claim 13
Dependent Claim
32 words
The plasma reactor according to any one of claims 11 or 12, wherein said gas injection device (35) is including one or more etchant species constituting greater than 50% of said gas.
Claim 14
Dependent Claim
24 words
The plasma reactor according to any one of claims 11 to 13, wherein said bias power frequency is about or greater than 6 MHz.
Claim 15
Dependent Claim
20 words
The plasma reactor according to any one of claims 11 to 14, source power is in excess of 1000 Watts.
Claim 16
Dependent Claim
20 words
The plasma reactor according to any one of claims 11 to 15, wherein said RF frequency is about 2.0 MHz.
Claim 17
Dependent Claim
25 words
The plasma reactor according to any one of claims 11 to 16, wherein said etchant species constitutes about or greater than 70% of said gas.
Claim 18
Dependent Claim
22 words
The plasma reactor according to any one of claims 11 to 17, wherein said etchant species constitutes about 80% of said gas.
Claim 19
Dependent Claim
23 words
The plasma reactor according to any one of claims 11 to 18, wherein said etchant species constitutes greater than 80% of said gas.
Claim 20
Dependent Claim
37 words
The plasma reactor according to any one of claims 11 to 19, wherein said wafer (45) as a top thin film layer with preliminarily defined features on said top thin film layer which are to be etched.
Claim 21
Dependent Claim
43 words
The plasma reactor of Claim 20 wherein said wafer (45) as a layer of photoresist over areas of said top thin film layer which are not to be etched, said photoresist comprising a material which is resistant to attack by said etchant species.
Claim 22
Dependent Claim
17 words
The plasma reactor of Claim 20 or 21, wherein said top thin film layer is a metal.
Claim 23
Dependent Claim
18 words
The plasma reactor according to any one of claims 11 to 22, wherein said etchant species comprises chlorine.
Claim 24
Dependent Claim
20 words
The plasma reactor according to any one of claims 11 to 23 wherein said gas further comprises plural etchant species.
Claim 25
Dependent Claim
35 words
The plasma reactor according to any one of claims 11 to 24, wherein said gas comprises a primary etchant species comprising at least one gas from a class of gases including BCl₃, HCl and HBr.
Claim 26
Dependent Claim
36 words
The plasma reactor according to any one of claims 11 to 24, wherein said gas comprises a primary etchant species constituting chlorine and a secondary etchant species comprising at least one of HCl, BCl₃ and HBr.
Claim 27
Dependent Claim
20 words
The etch process according to any one of claims 1 to 10, wherein said gas further comprises plural etchant species.
Claim 28
Dependent Claim
44 words
The etch process according to any one of claims 1 to 10 or 27, wherein said gas comprises a primary etchant species constituting chlorine and a secondary etchant species comprising at least one gas from a class of gases including BCl₃, HCl and HBr.
Claim 29
Dependent Claim
38 words
The etch process according to any one of claims 1 to 10 or 27, wherein said gas comprises a primary etchant species constituting chlorine and a secondary etchant species comprising at least one of HCl, BCl₃ and HBr.
Claim 30
Dependent Claim
150 words
A plasma reactor, especially for etching a conductive film on a wafer, comprising: a reactor vacuum chamber (10) adapted to receive a wafer (45) bearing a conductive film to be etched; at least one or more controlled gas supply outlet openings (40) within said chamber (10) adapted to introduce into said chamber (10) at least one etchant gas capable of being ionised into a reactant species for etching said conductive film at an etchant gas concentration which is a substantial fraction of the total gas composition within the chamber; a coil inductor (20) positioned about said chamber (10); and a first power source (25) connected to said inductor (20) for applying RF power thereto of at least 750 Watts at an RF frequency of about or less than 6 MHz to maintain a high density plasma of said gas primarily by inductively coupling RF power between said coil and plasma.
Claim 31
Dependent Claim
35 words
The reactor of Claim 30, wherein the gas within the chamber (10) includes a plurality of etchant gases, and in which a first etchant gas comprises the primary component of said plurality of etchant species.
Claim 32
Dependent Claim
20 words
The reactor of Claim 30 or 31 wherein substantially over half of the etchant gases constitute said first etchant gas.
Claim 33
Dependent Claim
18 words
The reactor according to any one of claims 30 to 32, wherein said first etchant gas comprises Chlorine.
Claim 34
Dependent Claim
49 words
The reactor according to any one of claims 30 to 33, further comprising a pedestal (50) within said chamber (10) supporting the wafer (45) and a second power source (55) connected to said pedestal (50) for applying thereto an RF bias at a frequency of at least 1 MHz.
Claim 35
Dependent Claim
29 words
The reactor according to any one of claims 11 to 26 or 30 to 34, wherein said chamber pressure is maintained in the range of 0 to 100 milliTorr.
Claim 36
Dependent Claim
113 words
An etch process, especially for etching a conductive film on a wafer in a plasma reactor, having an inductor coil for irradiating the reactor with RF power, the process comprising the steps of: introducing into the reactor at least one etchant gas ionizable into a reactant species for etching the conductive film at an etchant gas concentration which is a substantial fraction of the total gas composition within the reactor; and coupling RF energy via said coil into the reactor at a power level of at least about 750 Watts and a frequency of about or less than 6 MHz to maintain a high density plasma within said reactor primarily by inductive coupling.
Claim 37
Dependent Claim
34 words
The process of Claim 36, wherein the gas within the chamber includes a plurality of etchant gases, and in which a first etchant gas comprises the primary component of said plurality of etchant species.
Claim 38
Dependent Claim
20 words
The process of Claim 36 or 37 wherein substantially over half of the etchant gases constitute said first etchant gas.
Claim 39
Dependent Claim
16 words
The process of any of Claims 36 to 38 wherein said first etchant gas comprises Chlorine.
Claim 40
Dependent Claim
43 words
The process of any of Claims 36 to 39 wherein said reactor comprises a pedestal within said chamber supporting the wafer, said process further comprising the step of applying an RF bias to said pedestal at a frequency of at least 1 MHz.
Claim 41
Dependent Claim
28 words
The process of any of Claims 36 to 40 further comprising the step of maintaining the chamber at a pressure in the range of 0 to 100 milliTorr.
References Cited (Backward Citations)
No citation records indexed.
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