EP0421430A2
Expired / Lapsed
EP
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A plasma process, method and apparatus
Assignee: Applied Materials Inc
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Filing: 1990-10-04
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Granted: —
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Expires: 2010-10-04
Abstract
Abstract A plasma process method and apparatus capable of operation significantly above 13.56 MHz can produce reduced self-bias voltage of the powered electrode to enable softer processes that do not damage thin layers that are increasingly becoming common in high speed and high density integrated circuits. A nonconventional match network is used to enable elimination of reflections at these higher frequencies. Automatic control of match network components enables the rf frequency to be adjusted to ignite the plasma and then to operate at a variable frequency selected to minimize process time without significant damage to the integrated circuit.
Inventors
- 👤 Donald M. Mintz
- 👤 Hiroji Hanawa
- 👤 Sasson Somekh
- 👤 Dan Maydan
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 13:18
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32009; H01J37/32082; H01J37/32174; H10; H10P; H10P14/00; H10P14/20
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
92 words
A plasma process method comprising the steps of: (a) igniting a plasma within a reactor chamber in a plasma reactor. (b) maintaining within said reactor chamber a gas pressure in the range 0.5 - 30 milliTorr*; and (c) providing rf power to a powered electrode at which a wafer is placed for processing within the reactor chamber, said power being supplied at a power level P sufficient to maintain a plasma within the reactor chamber and at a frequency f > 13.56 MHz that is selected to optimize processing of the wafer.
Claim 2
Dependent Claim
92 words
A plasma process method comprising the steps of: (a) igniting a plasma within a reactor chamber in a plasma reactor. (b) maintaining within said reactor chamber a gas pressure in the range 0.5 - 30 milliTorr*; and (c) providing rf power to a powered electrode at which a wafer is placed for processing within the reactor chamber, said power being supplied at a power level P sufficient to maintain a plasma within the reactor chamber and at a frequency f > 13.56 MHz that is selected to optimize processing of the wafer.
Claim 3
Dependent Claim
16 words
A method as in claim 1 wherein the frequency f is in the range 30-200 MHz.
Claim 4
Dependent Claim
30 words
A method as in claim 1 or 2 wherein the frequency f is in the range 50-70 MHz, whereby this method is particularly suitable for a soft plasma etch process.
Claim 5
Dependent Claim
32 words
A method as in claim 1 or 2 wherein the frequency f is greater than 137 MHz, whereby this method is particularly suitable for plasma cleaning and plasma enhanced chemical vapor deposition.
Claim 6
Independent Claim
47 words
A method as in one of claims 1 to 3 wherein, in step (b), the power P and frequency f are selected to produce a powered electrode negative self-bias that is less than 350 volts, whereby this method is particularly suitable for a soft plasma etch process.
Claim 7
Dependent Claim
39 words
A method as in claim 5 wherein the power and frequency are selected to produce at the powered electrode a negative self-bias voltage greater than 150 volts, whereby this method is particularly suitable for a nonreactive soft etch process.
Claim 8
Dependent Claim
40 words
A method as in claim 5 wherein the power and frequency are selected to produce at the powered electrode a negative self-bias voltage greater than 50 volts, whereby this method is particularly suitable for a soft reactive ion etch process.
Claim 9
Independent Claim
67 words
A method as in one of claims 1 to 7, wherein in step (a), rf power is supplied to said power electrode through a match network that is detuned to produce a sufficiently strong self-bias field at the powered electrode that an avalanche of electrons is produced that ignites said plasma, said method further comprising the step (a1) tuning said match network to substantially eliminate reflected power.
Claim 10
Independent Claim
48 words
A method as in one of the preceding claims further comprising the step of: (a1) adjusting a match network such that, at a selected frequency f for use during etch of a wafer, there is substantially no reflection of power back to a source of said rf power.
Claim 11
Dependent Claim
26 words
A method as in claim 1 wherein the frequency f is 40.68 MHz, whereby radiation power level restrictions are less restrictive than at non ISM frequencies.
Claim 12
Independent Claim
48 words
A method as in one of the preceding claims wherein the said plasma is generated in a gas selected from the set consisting of pure argon, pure hydrogen, gas mixtures including fluorine-containing gases and gas mixtures including chlorine-containing gases, whereby this method is particularly suitable for wafer cleaning.
Claim 13
Independent Claim
48 words
A method as in one of claims 1 to 10 wherein the said plasma is generated in a gas selected from the set consisting of pure argon, gas mixtures including fluorine-containing gases and gas mixtures including chlorine-containing gases, whereby this method is particularly suitable for an etching process.
Claim 14
Independent Claim
40 words
a method as in one of claims 1 to 10 wherein the said plasma is generated in a gas selected from the set consisting of pure argon, silane, and TEOS, whereby this method is particularly suitable for chemical vapor deposition.
Claim 15
Dependent Claim
65 words
A plasma process apparatus comprising: a plasma reactor (11) having a powered electrode (16) on which a wafer (17) is to be placed for processing; and an rf power supply (15) that produces power at a frequency f in the range 13.56 MHz < f < 200 MHz, said frequency f being selected to optimize a wafer process to be carried out in said reactor.
Claim 16
Dependent Claim
65 words
A plasma process apparatus comprising: a plasma reactor (11) having a powered electrode (16) on which a wafer (17) is to be placed for processing; and an rf power supply (15) that produces power at a frequency f in the range 13.56 MHz < f < 200 MHz, said frequency f being selected to optimize a wafer process to be carried out in said reactor.
Claim 17
Dependent Claim
45 words
A plasma process apparatus as in claim 14 further comprising a match network (112) at an rf power input to the powered electrode, said match network being capable of substantially eliminating reflections of rf signal at frequencies in the range from 13.56 to 200 MHz.
Claim 18
Dependent Claim
37 words
A plasma process apparatus as in claim 14 or 15 wherein the match network (112) is tunable over a frequency range, thereby enabling adjustment of frequency to optimize plasma process conditions for a variety of process processes.
Claim 19
Dependent Claim
18 words
A plasma process apparatus as in one of claims 14 to 16 wherein said reactor is rf shielded.
Claim 20
Dependent Claim
19 words
A plasma process apparatus as in claims 14 to 17 wherein the frequency is within the range 30-200 MHz.
Claim 21
Dependent Claim
28 words
A plasma process apparatus as in claim 18 wherein the frequency is in the range 50-70 MHz, whereby this apparatus is particularly suitable for a plasma etch process.
Claim 22
Dependent Claim
36 words
A plasma process apparatus as in one of claims 14 to 18 wherein the frequency is greater than 137 MHz, whereby this apparatus is particularly suitable for wafer cleaning and plasma enhanced chemical vapor deposition processes.
Claim 23
Dependent Claim
22 words
A plasma process apparatus as in one of claims 14 to 18 wherein the frequency is the ISM standard frequency 40.68 MHz.
Claim 24
Dependent Claim
62 words
A plasma process apparatus as in one of claims 14 to 21 further comprising means (114, 115), for producing within said process apparatus a magnetic field parallel to the wall that is sufficiently weak that it does not significantly affect process rate or uniformity and that is sufficiently strong that it substantially eliminates desorption from interior walls of said plasma process apparatus.
Claim 25
Dependent Claim
22 words
A plasma process apparatus as in claim 22 wherein said magnetic field, at said interior walls, is in the range 1-20 Gauss.
References Cited (Backward Citations)
No citation records indexed.
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