EP0840365A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
High pressure plasma oxide etch process
Assignee: Applied Materials Inc
•
Filing: 1997-10-16
•
Granted: —
•
Expires: 2017-10-16
Abstract
Abstract The invention is embodied in a method of processing a semiconductor workpiece in a plasma reactor chamber, including supplying a polymer and etchant precursor gas containing at least carbon and fluorine into the chamber at a first flow rate sufficient of itself to maintain a gas pressure in the chamber in a low pressure range below about 20mT, supplying a relatively non-reactive gas into the chamber at second flow rate sufficient about one half or more of the total gas flow rate into the chamber, in combination with the first flow rate of the precursor gas, to maintain the gas pressure in the chamber in a high pressure range above 20mT, and applying plasma source power into the chamber to form a high ion density plasma having an ion density in excess of 10 10 ions per cubic centimeter. In one application of the invention, the workpiece includes an oxygen-containing overlayer to be etched by the process and a non-oxygen-containing underlayer to be protected from etching, the precursor gas dissociating in the plasma into fluorine-containing etchant species which etch the oxygen-containing layer and carbon-containing polymer species which accumulate on the non-oxygen-containing underlayer. Alternatively, the high pressure range may be defined as a pressure at which the skin depth of the inductive field exceeds 1/10 of the gap between the inductive antenna and the workpiece.
Inventors
- 👤 Kenneth Collins
- 👤 David Groechel
- 👤 Raymond Hung
- 👤 Michael Rice
- 👤 Gerald Zheyao Yin
- 👤 Jian Ding
- 👤 Chunshi Cui
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 13:19
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/20; H10P70/23; H10P70/234; C; C23; C23C; C23C16/00; C23C16/44; C23C16/50; C23C16/517; H01; H01F; H01F29/00; H01F29/14; H01F29/143; H01J; H01J37/00; H01J37/32; H01J37/32009; H01J37/32082; H01J37/321; H01J37/32137; H01J37/32146; H01J37/32155; H01J37/32165; H01J37/32431; H01J37/32458; H01J37/32467; H01J37/32522; H01J37/3266; H01J37/32688; H01J37/32697; H01J37/32706; H01J37/32798; H01J37/32853; H01J37/32871; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10P72/00; H10P72/70; H10P72/72; H01J2237/00; H01J2237/32; H01J2237/33; H01J2237/334; H01J2237/3343; H01J2237/3345; H01J2237/3346
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
122 words
A method of processing a semiconductor
workpiece in a plasma reactor chamber, comprising: supplying a polymer and etchant precursor
gas containing at least carbon and fluorine into said
chamber at a first flow rate sufficient of itself to
maintain a gas pressure in said chamber in a low
pressure range below about 20mT; supplying a relatively non-reactive gas into
said chamber at a second flow rate sufficient, in
combination with the first flow rate of said precursor
gas, to maintain said gas pressure in said chamber in
a high pressure range above about 20mT; and applying plasma source power into said
chamber to form a high ion density plasma having an
ion density in excess of 10 10 ions per cubic
centimeter.
Claim 2
Dependent Claim
20 words
A method as claimed in Claim 1, wherein said
applying plasma power comprises inductively coupling
plasma power into said chamber.
Claim 3
Independent Claim
178 words
A method of processing a semiconductor
workpiece in a plasma reactor chamber having an
inductive antenna overlying said workpiece and
defining a gap distance therebetween, said inductive
antenna producing an inductive field at a particular
RF frequency with an inductive field skin depth which
is a function of gas pressure in said reactor chamber,
said process comprising: supplying a polymer and etchant precursor
gas containing at least carbon and fluorine into said
chamber at a first flow rate sufficient of itself to
maintain a gas pressure in said chamber in a low
pressure range where said skin depth does not greatly
exceed 1/10 of said gap distance; supplying a relatively non-reactive gas into
said chamber at a second flow rate sufficient, in
combination with the first flow rate of said precursor
gas, to maintain said gas pressure in said chamber in
a high pressure range where said skin depth is greater
than 1/10 of said gap distance; and applying plasma source power at said
particular RF frequency to said inductive antenna to
inductively couple power into said chamber.
Claim 4
Dependent Claim
18 words
A method as claimed in Claim 3, wherein said
high pressure range is in excess of 20 mT.
Claim 5
Dependent Claim
23 words
A method as claimed in Claim 4, further
comprising applying RF bias power to said workpiece to
control plasma electron and ion energy.
Claim 6
Dependent Claim
37 words
A method as claimed in Claim 5, wherein said
plasma electron energy is sufficient to ionize said
non-reactive gas and to provide sufficient ion energy
to suppress net polymer accumulation on non-oxygen
containing surfaces of said workpiece.
Claim 7
Independent Claim
110 words
A method of processing a semiconductor
workpiece in a plasma reactor chamber, comprising: supplying a polymer and etchant precursor
gas containing at least carbon and fluorine into said
chamber at a first flow rate sufficient of itself to
maintain a gas pressure in said chamber in a low
pressure range below about 20mT; supplying a relatively non-reactive gas into
said chamber at a second flow rate sufficient, in
combination with the first flow rate of said precursor
gas, to maintain said gas pressure in said chamber in
a high pressure range above about 20 mT; and inductively coupling plasma source power
into said chamber to produce an inductively coupled
plasma.
Claim 8
Independent Claim
29 words
A method as claimed in any one of Claims 1
to 7, wherein said high pressure range is in excess of
50 mT, preferably in excess of 100 mT.
Claim 9
Independent Claim
46 words
A method as claimed in any one of Claims 5
to 8, wherein said plasma source power is sufficient
to provide an ion density of said plasma in excess of
10 10 ions per cubic centimeter, preferably in excess of
10 11 ions per cubic centimeter.
Claim 10
Independent Claim
35 words
A method a claimed in any one of Claims 1 to
9, wherein said second flow rate is at least about 0.3
of the total flow rate of all gases supplied into said
reactor chamber.
Claim 11
Independent Claim
26 words
A method as claimed in any one of Claims 1
to 10, further comprising applying RF bias power to
said workpiece to control plasma ion energy.
Claim 12
Dependent Claim
26 words
A method as claimed in Claim 11, wherein
said plasma ion energy is sufficient to suppress net
polymer accumulation on non-oxygen containing surfaces
of said workpiece.
Claim 13
Independent Claim
36 words
A method as claimed in any one of Claims 3
to 12, further comprising controlling a temperature of
a surface within said chamber to balance polymer
accumulation on said workpiece with polymer removal
from said workpiece.
Claim 14
Independent Claim
52 words
A method as claimed in any one of Claims 3
to 13, wherein said etchant and polymer precursor gas
comprises a low-carbon content etchant and polymer
precursor gas and a high-fluorine content etchant and
polymer precursor gas in a ratio which balances
accumulation on said workpiece with polymer removal
from said workpiece.
Claim 15
Independent Claim
90 words
A method of processing a semiconductor
workpiece in a plasma reactor chamber, comprising: supplying a polymer and etchant precursor
gas containing at least carbon and fluorine into said
chamber at a first flow rate; supplying a relatively non-reactive gas into
said chamber at a second flow rate which is at least
0.30 of the total flow rates of all gases into said
chamber; and applying plasma source power into said
chamber to form a high ion density having an ion
density in excess of 10 10 ions per cubic centimeter.
Claim 16
Independent Claim
27 words
A method as claimed in any one of Claims 1,
2 or 15, wherein said ion density is in excess of 10 11 ions per cubic centimeter.
Claim 17
Independent Claim
71 words
A method of processing a semiconductor
workpiece in a plasma reactor chamber, comprising: supplying a polymer and etchant precursor
gas containing at least carbon and fluorine into said
chamber at a first flow rate; supplying a relatively non-reactive gas into
said chamber at second flow rate which is at least
0.30 of the total flow rate of all gases into said
chamber; and inductively coupling plasma source power
into said chamber.
Claim 18
Independent Claim
60 words
A method as claimed in any one of Claims 1
to 17, wherein said workpiece comprises an oxygen-containing
overlayer to be etched by said process and
a non-oxygen-containing underlayer to be protected
from etching, said precursor gas dissociating in said
plasma into fluorine-containing etchant species which
etch said oxygen-containing layer and carbon-containing
polymer species which accumulate on said
non-oxygen-containing underlayer.
Claim 19
Dependent Claim
19 words
A method as claimed in Claim 18, further
comprising providing a source of fluorine scavenging
species in said chamber.
Claim 20
Dependent Claim
27 words
A method as claimed in Claim 19, wherein
said fluorine scavenging species source comprises a
solid article in said chamber or a gas introduced into
said chamber.
Claim 21
Dependent Claim
22 words
A method as claimed in Claim 19 or Claim 20,
further comprising supplying an etch stop inhibitor
gas into said reactor chamber.
Claim 22
Independent Claim
47 words
A method as claimed in any one of Claims 1
to 21, wherein said second flow rate is at least .50
the flow rates of all gases supplied into said reactor
chamber, preferably at least .70 the flow rates of all
gases supplied into said reactor chamber.
Claim 23
Independent Claim
27 words
A method as claimed in any one of Claims 1
to 22, wherein said non-reactive gas comprises one of:
(1) argon, (b) helium, (c) neon, (c) xenon.
Claim 24
Independent Claim
38 words
A method as claimed in any one of Claims 15
to 23, further comprising applying RF bias power to
said workpiece to provide sufficient ion energy to
suppress net polymer accumulation on non-oxygen
containing surfaces of said workpiece.
Claim 25
Independent Claim
41 words
A method as claimed in any one of Claims 1,
2 or 24, further comprising controlling a temperature
of a surface within said chamber to provide a desired
apportionment between polymer accumulation on said
workpiece and polymer removal from said workpiece.
Claim 26
Independent Claim
57 words
A method as claimed in any one of Claims 1
to 25, wherein said etchant and polymer precursor gas
comprises a low-carbon content etchant and polymer
precursor gas and a high-fluorine content etchant and
polymer precursor gas in a ratio which provides a
desired apportionment between polymer accumulation on
said workpiece and polymer removal from said
workpiece.
Claim 27
Independent Claim
29 words
A method as claimed in any one of Claims 19
to 26, wherein said source of fluorine scavenger
species comprises a solid silicon-containing material
or a solid carbon-containing material.
Claim 28
Independent Claim
21 words
A method as claimed in any one of Claims 19
to 27, further comprising heating said source of
fluorine scavenger species.
Claim 29
Independent Claim
25 words
A method as claimed in any one of Claims 19
to 28, further comprising applying an RF bias to said
source of fluorine scavenger species.
Claim 30
Dependent Claim
38 words
A method as claimed in Claim 29, wherein
said applying an RF bias comprises applying an RF bias
to said workpiece, whereby an RF bias is capacitively
coupled from said workpiece to said source of fluorine
scavenger species.
Claim 31
Independent Claim
30 words
A method as claimed in any one of claims 19
to 26, wherein said providing a source of fluorine
scavenging species comprises introducing a fluorine
scavenger-containing gas into said chamber.
Claim 32
Dependent Claim
52 words
A method as claimed in Claim 31, wherein
said gas is a silicon-containing gas comprising at
least one of silane, tetraethoxysilane, diethylsilane
or silicon tetrafluoride, or wherein said gas is a
hydrogen containing gas comprising at least one of
silane, pure hydrogen gas, a hydrocarbon gas, methane,
hydrogen fluoride, a fluoro-hydrocarbon gas.
Claim 33
Independent Claim
47 words
A method as claimed in any one of Claims 17
to 32, wherein said inductive coupling is sufficient
to provide a high density plasma having an ion density
greater than about 10 10 ions per cubic centimeter,
preferably greater than about 10 11 ions per cubic
centimeter.
Claim 34
Independent Claim
42 words
A method as claimed in any one of Claims 1
to 33, further comprising maintaining a gas pressure
in said chamber in excess of about 20 mT, preferably
in excess of about 50 mT, more preferably in excess of
about 70 mT.
Claim 35
Independent Claim
33 words
A method as claimed in any one of Claims 19
to 34, further comprising applying an RF bias to said
source of fluorine scavenger species and heating said
source of fluorine scavenger species.
Claim 36
Independent Claim
91 words
A method of processing a semiconductor
workpiece in a plasma reactor chamber comprising: supplying a polymer and etchant precursor
gas containing at least carbon and fluorine into said
chamber; supplying a relatively non-reactive gas into
said chamber; maintaining the flow rate of the non-reactive
gas at a significant fraction of that of the
total flow rates of all gases into said chamber; and inductively coupling plasma source power
into said chamber to produce an inductively coupled
plasma having a high ion density in excess of 10 10 ions
per cubic centimeter.
Claim 37
Independent Claim
85 words
A method of processing a semiconductor
workpiece in a plasma reactor chamber comprising: supplying a polymer and etchant precursor
gas containing at least carbon and fluorine into said
chamber; supplying a relatively non-reactive gas into
said chamber; maintaining the flow rate of the non-reactive
gas at a significant fraction of that of the
total flow rates of all gases into said chamber
sufficiently to maintain a pressure inside said
chamber in excess of about 20 mT; and inductively coupling plasma source power
into said chamber.
References Cited (Backward Citations)
No citation records indexed.
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